After replacing an old person by a new person, it was found that the average age of five persons of a assembly is the same as it was 6 years ago. What is the difference between the ages of the replaced and the new persons? A) 24 B) 36 C) 30 D) 15

After replacing an old person by a new person, it was found that the average age of five persons of a assembly is the same as it was 6 years ago. What is the difference between the ages of the replaced and the new persons? A) 24 B) 36 C) 30 D) 15 
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1 Answer

Answer :

C)

Let the ages of the five persons at present be a, b, c, d & e years.

And the age of the new persons be f years.

So the new average of five members' age = (a + b + c + d + f)/5 ------- (1)

Their corresponding ages 6 years ago = (a-6), (b-6), (c-6), (d-6) & (e-6) years

So their average age 6 years ago = (a + b + c + d + e - 30)/5 = x ----- (2)

==> a + b + c + d + e = 5x + 30

==> a + b + c + d = 5x + 30 - e ------ (3)

Substituting this value of a + b + c + d = 5x + 30 - e in (1) above,

The new average is: (5x + 30 - e + f)/5

Equating this to the average age of x years, 6yrs, ago as in (2) above,

(5x + 30 - e + f)/5 = x

==> (5x + 30 - e + f) = 5x

Solving e - f = 30 years.

Thus the difference of ages between replaced and new person = 30years.
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Related questions

The average age of K and L is 48 years. If M replaced K, the average age would be 40 and if M replaced L, the average would be 44. What are the ages of K,L,M repectively? A) 58, 46, 22 B) 32, 44, 36 C) 52,44,36 D) 56, 22,38

Description :  The average age of K and L is 48 years. If M replaced K, the average age would be 40 and if M replaced L, the average would be 44. What are the ages of K,L,M repectively? A) 58, 46, 22 B) 32, 44, 36 C) 52,44,36 D) 56, 22,38

Last Answer : Answer: C)  Total age of K& L = 48*2 = 96 yrs----->1 Total age of L& M = 40*2 = 80yrs----->2 Total age of K& M = 44*2 = 88 yrs----->3 from 1, 2, 3 K+L+M =132---->4 from 1 & 4, M= 36 from 2 & 4, K=52 from 3 & 4, L=44 Hence the required answer is 52,44,36 

The average age of a board of 8 trustless remains the same as it was 3 years ago, when one of them is replaced by a new member. The new member is younger than the truetee in whose place he has been replaced by (a) 24 years (b) 26 years (C) 47 years (d) 32 years

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Last Answer : 24 years 

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Description : The average age of A and B is 20 years. If C were to replace A, the average would be 19 and id C were to replace B,the average would be 21 . The ages of A, B and C are (in years) (a) 22, 17,16 (b) 22, 18, 20 (c) 30, 18, 15 (d) 23, 17 ,15

Last Answer : 22, 18, 20 Hint : A + B = 2 x 20 C + B = 2 x 19 A + C = 2 x 21

A person’s age is 150% of what it was 15 years ago, but 76% of what it will be after 15years. What is his present age? A) 39.7 B) 45.8 C) 42.8 D) 37.8

Description : A person’s age is 150% of what it was 15 years ago, but 76% of what it will be after 15years. What is his present age? A) 39.7 B) 45.8 C) 42.8 D) 37.8

Last Answer : B)  let the present age be X yrs then 150% of (X-15)=X; and 76 % of (x+15)= X 150% of (X-15)=76% of(X+15) 3/2(X-15)=19/25(X+15)  X=45.8yrs

A batch of 50 people has the oldest person with 160 years of age. The average of the batch is reduced by 2, if the oldest person is replaced by someone new, Find the age of the new person. A) 45 B) 30 C) 60 D) 75

Description : A batch of 50 people has the oldest person with 160 years of age. The average of the batch is reduced by 2, if the oldest person is replaced by someone new, Find the age of the new person. A) 45 B) 30 C) 60 D) 75

Last Answer : Answer: C)  Average=Sum of observations/Number of observations Given, a batch of 50 people has the oldest person with 160 years of age. Let the average of the group be a'. Sum total of ages = 50 a Given, average of the ... person be b' . 50a - 160 + b = 50(a - 2) b= 160-100 b = 60 years

Rohit married 21 years ago at the age of 90 years. His wife's present age 99years. If 24 years later the average age of rohit, his wife and their son was 90 years, then what is son's present age? A) 15yr B) 14yr C) 13yr D) 12yr

Description : Rohit married 21 years ago at the age of 90 years. His wife's present age 99years. If 24 years later the average age of rohit, his wife and their son was 90 years, then what is son's present age? A) 15yr B) 14yr C) 13yr D) 12yr

Last Answer : Answer: D) Rohit present age = 111years total age of family after 24 yrs = 90*3= 270 present age of rohit & his wife = 111+99 = 210yrs present age of rohit, his wife & his son= 270- 24*3 =198 present age of son= 210-198=12yrs

The average age of 160 boys in a class is 58 yrs. The average group of 30 boys in the class is 42 yrs and the average of another group of 50 boys in the class is 36 years. What is the average age of the remaining boys? A) 72.58 B) 74.25 C) 77.75 D) 75.68

Description : The average age of 160 boys in a class is 58 yrs. The average group of 30 boys in the class is 42 yrs and the average of another group of 50 boys in the class is 36 years. What is the average age of the remaining boys? A) 72.58 B) 74.25 C) 77.75 D) 75.68 

Last Answer : C) Total age of 160 boys = 160* 58= 9280 total age of 30 boys = 30 * 42= 1260 total age of next 50boys = 50 * 36= 1800 average of the remaining boys = [(9280-{1260+1800})/[160 - (30 + 50)] =>9280-3060/80 =>6220/80 =77.75yrs

20 years ago, the average age of a family of 4 member was 48 years. 2 children having been born (with the age difference of4 yrs) the present average age of the family is the same. The present age of the youngest child is. A) 2yrs B) 4 yrs C) 6yrs D) 8yrs

Description : 20 years ago, the average age of a family of 4 member was 48 years. 2 children having been born (with the age difference of4 yrs) the present average age of the family is the same. The present age of the youngest child is. A) 2yrs B) 4 yrs C) 6yrs D) 8yrs

Last Answer : C) Total age of 4 members, 20 yrs ago = (48 * 4)=192 yrs Total age of 4 members now = 192 + 20 * 4 = 272 yrs Total age of 6 members now = (48*6)=288yrs Sum of the age of children = 288 - 272 = 16 ... the age of the elder child 4 +x So x + 4 +x = 16 2x=12 X=6 Age of younger child = 6years

The average monthly salary of 24 labours and 6 supervisor in a factory was Rs. 1200. When one of the supervisor whose salary was Rs. 1440, was replaced with a new supervisor, then the average salary of the team went down to 1160. What is the salary of the new supervisor? A) 170 B) 420 C) 390 D) 240

Description : The average monthly salary of 24 labours and 6 supervisor in a factory was Rs. 1200. When one of the supervisor whose salary was Rs. 1440, was replaced with a new supervisor, then the average salary of the team went down to 1160. What is the salary of the new supervisor? A) 170 B) 420 C) 390 D) 240

Last Answer : D) The total salary amount = 30 1200=36000 The salary of the exiting supervisor = 1440 Therefore, the salary of 24 labours and the remaining 5 supervisors: =36000-1440=34560 When a new ... 34800=1200 less than that of the old supervisor who left the company, which is equal to 1440−1200=240

The average age of 14 mens is increased by 1 year when one of them whose age is 44 years is replaced by a lady. What is the age of the lady? A) 54 B) 58 C) 50 D) 56

Description : The average age of 14 mens is increased by 1 year when one of them whose age is 44 years is replaced by a lady. What is the age of the lady? A) 54 B) 58 C) 50 D) 56 

Last Answer : B) suppose the average age of 14 men is x years and the age of lady is y years. the total age of 14 mens will be = 14x years the average age of 14 mens is increased by 1 years who of them whose age is 44 years is replaced by ... 14x - 44 + y = 14* (x+1) 14x - 44 + y = 14x + 14 y = 14+ 44 y=58

4 years ago, the average age of x and y was 22 years. With z joining them, the average becomes 26 years. How ols is z now? A) 62yrs B) 50yrs C) 38 yrs D) 54yrs

Description :  4 years ago, the average age of x and y was 22 years. With z joining them, the average becomes 26 years. How ols is z now? A) 62yrs B) 50yrs C) 38 yrs D) 54yrs

Last Answer : C) age of (x+y) 4 yrs ago= (22 * 2)yrs =44 age of (x+y+z)=(26 *3)yrs =78yrs Therefore z’s age = (78-44)yrs =34 yrs. Current age of z =38 yrs

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Description : The sum of the ages of two persons A and B is 50. 5 years ago, the ratio of their ages was 5/3. The present age of A and B are (A) 30, 20 (B) 35, 15 (C) 38, 12 (D) 40, 10

Last Answer : Answer: A

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Description : The average age of Krishnan family of 10 members was 34 yrs, 3 yrs ago. A baby having been born, the average age of the family is the same today. The present age of the baby. A) 1yr B) 3yrs C) 4yrs D) 2yrs

Last Answer : C) Total age of 10 members , 3 yrs ago = (34*10)yrs = 340 yrs Total age of 10 members now = (340 +3*10) =370yrs Total age of 11 members now = (34*11)yrs =374yrs Therefore age of the baby= 374 – 370 =4yrs.

The average age of 78 students of a batch is 30 years. If the age of the head master be included, then the average increases by 6 months. Find the age of head master? A) 56yrs 5 months B) 66yrs 6 months C) 56yrs 5 months D) 69yrs 5 months

Description : The average age of 78 students of a batch is 30 years. If the age of the head master be included, then the average increases by 6 months. Find the age of head master? A) 56yrs 5 months B) 66yrs 6 months C) 56yrs 5 months D) 69yrs 5 months

Last Answer : D)  Total age of 78 students = (780 * 30)yrs  = 2340 yrs  Average of 79 persons = 30 yrs 6 months  = 6 ½ yrs  Total age of 79 persons = 61/2 * 79  = 2409.5  Age of headmaster = (2409.5 – 2340)yrs  = 69.5 yrs = 69 yrs 5 months.

The average age of a family of 24 members is 132 years. If the age of the youngest member is 22 years, the average age of the family at the birth of the youngest member was? A) 75 B) 110 C) 100 D) 95

Description : The average age of a family of 24 members is 132 years. If the age of the youngest member is 22 years, the average age of the family at the birth of the youngest member was? A) 75 B) 110 C) 100 D) 95

Last Answer :  Answer: B) Total age of the family of 24 members = 132* 24 = 3168 yrs Total age of the family members 22 yrs ago = 3168 - (24*22) = 2640 at the time total members in a family = 24 average age of the family at the birth of the youngest member = 2640/24 = 110yrs.

Eight years ago, the ratio of the ages of micky and Donald was 6:5, 12years hence, the ratio of their ages will be 11:10. What is Donald age at present a) 30 years b) 28 years c) 34 years d) 36 years

Description : Eight years ago, the ratio of the ages of micky and Donald was 6:5, 12years hence, the ratio of their ages will be 11:10. What is Donald age at present a) 30 years b) 28 years c) 34 years d) 36 years

Last Answer : B Let 8 years ago the age of Micky and Donald be 6x and 5x resp. then, ((6x+8)+12) / ((5x+8)+12) = 11/10 10(6x+20) = 11(5x+20) 5x = 20 => x = 4 So Donald age is (5x+8) = 28

The average age of Anu, banu and tonu is 74 yrs. 10years hence the average age of anu and tonu is 86 yrs.6yrs ago the average age of aarthi and banu was 72 yrs. Find the present age of aarthi. A) 80 B) 86 C) 84 D) 83

Description : The average age of Anu, banu and tonu is 74 yrs. 10years hence the average age of anu and tonu is 86 yrs.6yrs ago the average age of aarthi and banu was 72 yrs. Find the present age of aarthi. A) 80 B) 86 C) 84 D) 83

Last Answer : B) anu+ banu+ tonu = 74 * 3 = 222yrs 10yrs hence, anu + 10 + tonu +10 = 86 * 2 anu + tonu= 152 banu = 222-152 = 70 yrs aarthi -6 + banu - 6= 72 * 2 aarthi + banu = 144 + 12 = 156 aarthi age = 156-70 aarthi age = 86yrs

Five years ago, the age of Arun was 4 times the age of Sarmi after 10 years, Arun will be twice as old as Sarmi. Find the Present ages of Arun and sarmi? a) 30 years, 10.5 years b) 32 years, 11.5 years c) 34 years, 14.5 years d) 35 years, 12.5 years e) None of these

Description : Five years ago, the age of Arun was 4 times the age of Sarmi after 10 years, Arun will be twice as old as Sarmi. Find the Present ages of Arun and sarmi? a) 30 years, 10.5 years b) 32 years, 11.5 years c) 34 years, 14.5 years d) 35 years, 12.5 years e) None of these

Last Answer : Five years ago, x – 5/y – 5 = 4/1 x – 4y = – 15 —-(i) After 10 years, x + 10/y + 10 = 2/1 x – 2y = 10 —–(ii) From eqn (i) and (ii) => x = 35, y = 12.5 Answer: d)

The average of 12 numbers is 7.9. The average of 5 of them is 6.8, while the average of other five is 7.7. what is the average of the remaining 2 numbers? A) 10.25 B) 11.15 C) 12.65 D) 13.25

Description : The average of 12 numbers is 7.9. The average of 5 of them is 6.8, while the average of other five is 7.7. what is the average of the remaining 2 numbers? A) 10.25 B) 11.15 C) 12.65 D) 13.25

Last Answer : B) Sum of the remaining 2 numbers = [(12 * 7.9) – (586.8) – (5*7.7)]  = 94.8 – 34 – 38.5  = 22.3  Required average = 22.3 / 2  = 11.15

When the average age of a father, mother and their son was 90 years, the son got married and a child was born just 6 year after the marriage when child turned 14 years the average age of the family is 80yrs. Find the age of daughter - in - law at present? A) 55 B) 56 C) 57 D) 58

Description : When the average age of a father, mother and their son was 90 years, the son got married and a child was born just 6 year after the marriage when child turned 14 years the average age of the family is 80yrs. Find the age of daughter - in - law at present? A) 55 B) 56 C) 57 D) 58

Last Answer : B) total age of father, mother and son at the time of son's marriage = 90*3 =270 present age of family father, mother, son, daughter-in-law, child = (father, mother, son age at the time of marriage ... 60)+ daughter-in-law present age + 14 = 80*5 =400 daughter-in-law present age= 400-344 = 56yrs

The average age of two persons is 46 years. 16 years back the ratio between their ages were 1 : 2, then what is the difference between present ages of these two persons? 1) 16 years 2) 20 years 3) 24 years 4) 12 years 5) 8 years

Description : The average age of two persons is 46 years. 16 years back the ratio between their ages were 1 : 2, then what is the difference between present ages of these two persons? 1) 16 years 2) 20 years 3) 24 years 4) 12 years 5) 8 years

Last Answer : 2) 20 years

The average age of students of a college is 31.6 yrs. The average age of boys in the class is 32.8 yrs and that of girls is 30.8. The ratio of number of boys to the number of girls in the class. A) 2:3 B) 3:1 C) 1:3 D) 3:2

Description : The average age of students of a college is 31.6 yrs. The average age of boys in the class is 32.8 yrs and that of girls is 30.8. The ratio of number of boys to the number of girls in the class. A) 2:3 B) 3:1 C) 1:3 D) 3:2

Last Answer : A) Let the ratio be D:1.then, (D * 32.8) + ( 1* 30.8)= (D+1) * 31.6 32.8 D +30.8 = 31.6 D + 31.6 32.8 D – 31.6D = 31.6 – 30.8 1.2D = 0.8 D = 0.8/1/2 = 0.4/0.6 D = 2/3 Required ratio = 2/3 :1 = 2:3.

The average age of Mr and Mrs Rahim at the time of their marriage in 1981 was 56 yrs. On the occasion of their anniversary in 1986, they observed that the average age of their family had come down by 15 yrs compared to their age at the time of their marriage. This was due to the fact that their daughter varshini was born. What was the age of varshini in 1990? A) 6 B) 5 C) 4 D) 1

Description : The average age of Mr and Mrs Rahim at the time of their marriage in 1981 was 56 yrs. On the occasion of their anniversary in 1986, they observed that the average age of their family had come down by 15 yrs compared to ... varshini was born. What was the age of varshini in 1990? A) 6 B) 5 C) 4 D) 1

Last Answer : B) Sum of the ages of Mr and Mrs Rahim=56×2=112years Sum of the ages in 1986=41×3=123 years Sum of the ages of Mr and Mrs Rahim =112+10=122 Daughters age in 1986=123-122=1 years  Daughters age in 1990 =1+4=5 years.

12 years ago M was half of N in age. If the ratio of their present ages is 4 : 5, what will be the total of their present ages a) 30 b) 35 c) 36 d) 32

Description : 12 years ago M was half of N in age. If the ratio of their present ages is 4 : 5, what will be the total of their present ages a) 30 b) 35 c) 36 d) 32

Last Answer : C Let M's age 12 years ago = x years. Then, N's age 12 years ago = 2x years. (x + 12) / (2x+ l2) = 4/5 => x = 4. So, the total of their present ages =(x + 12 + 2x + 12) = (3x + 24) = 36 years.

The average age of three -seventh of class is 49, what should be the average of remaining four-seventh students so that the average of the entire class is 63? A) 24.5 B) 86.5 C) 73.5 D) 25.5

Description : The average age of three -seventh of class is 49, what should be the average of remaining four-seventh students so that the average of the entire class is 63? A) 24.5 B) 86.5 C) 73.5 D) 25.5

Last Answer : C) According to the question, 63=3/7×49+4/7×y 63=147/7+4y/7 441=147+4y 4y=294 Y=73.5

The sum of the ages of the 4 members of Sinha family is 172 years. 8 years ago the ages of the 4 members Nishu, Vicky, Mrs.Sinha and Sinha were in the ratio of 2:3:7:8. After how many years would Nishu be as old as the present age of his mother? a) 33 years b) 35 years c) 36 years d) 37 years e) None of these

Description : The sum of the ages of the 4 members of Sinha family is 172 years. 8 years ago the ages of the 4 members Nishu, Vicky, Mrs.Sinha and Sinha were in the ratio of 2:3:7:8. After how many years would Nishu be ... present age of his mother? a) 33 years b) 35 years c) 36 years d) 37 years e) None of these

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A man wnt uphill with a speed of 20 km.p.h. and came downhill with a speed of 30 km p.h. The average speed for his journey was (a) 25 km. p.h. (b) 22 1/2 km. p.h. (c) 24 km. p.h. (d) 25 1/2 km. p.h.

Description : A man wnt uphill with a speed of 20 km.p.h. and came downhill with a speed of 30 km p.h. The average speed for his journey was (a) 25 km. p.h. (b) 22 1/2 km. p.h. (c) 24 km. p.h. (d) 25 1/2 km. p.h.

Last Answer : 24 km.p.h.

Gowshik is going to market from his home by bike at a speed of 20kmph. While he comes back to his home with a speed of X kmph, what should be the value of x so that his average speed is 24kmph ? A) 24 B) 34 C) 30 D) 32

Description : Gowshik is going to market from his home by bike at a speed of 20kmph. While he comes back to his home with a speed of X kmph, what should be the value of x so that his average speed is 24kmph ? A) 24 B) 34 C) 30 D) 32

Last Answer : C) Let speed be X Average speed =2xy/(x+y) =>2×X×20/(x+20)=24 40x=24x+480 16x=480 X=30 kmph.

Harish buys petrol at rs 21, Rs.24 and Rs.27 per litre for 3 successive years. What approximately is the average cost per litre of petrol if he spends Rs.12000 each year? A) 23.74 B) 54.76 C) 24.66 D) 28.99

Description : Harish buys petrol at rs 21, Rs.24 and Rs.27 per litre for 3 successive years. What approximately is the average cost per litre of petrol if he spends Rs.12000 each year? A) 23.74 B) 54.76 C) 24.66 D) 28.99

Last Answer : A)  Total quantity of petrol consumed in 3 yr = (12000/21 +12000/24+12000/27) =12000(1/2 + 1/24 + 1/27) =12000(72+63+56/1512) =12000(191/1512) =(2292000/1512)litres Total amount spent = rs(3 *12000) = Rs.36000 Average cost = Rs(36000*1512/2292000) =Rs.23.74

At the average age of siva and sasi is equal to the average age of somu and ramu. if the ratio of age of siva and sasi 1:3 and somu age is equal to the three by two of siva age. What is the present age of somu if ramu age is 25years? A) 12 B) 15 C) 18 D) 21

Description : At the average age of siva and sasi is equal to the average age of somu and ramu. if the ratio of age of siva and sasi 1:3 and somu age is equal to the three by two of siva age. What is the present age of somu if ramu age is 25years? A) 12 B) 15 C) 18 D) 21

Last Answer : B) siva:sasi=x:3x siva+sasi/2=somu + ramu/2 X+3X=3/2×X+25 5X=50 X=10 Siva’s age is 10 then somu's age = 3/2×10=15 years

A group of 4 persons joins in javelin throw competition. The best player scored 42.5 points. If he had scored 46 points, the average score for the team would have been 42. The number of points the team scored. A) 164.5 B) 166.5 C) 169.7 D) 162.5

Description : A group of 4 persons joins in javelin throw competition. The best player scored 42.5 points. If he had scored 46 points, the average score for the team would have been 42. The number of points the team scored. A) 164.5 B) 166.5 C) 169.7 D) 162.5

Last Answer : A) Let the total score be ‘x’. (X+46 – 42.5)/4 = 42 X + 3.5 = 42 * 4 X + 3.5 = 168 X = 168 – 3.5 X = 164.5

In a famous restaurant rooms were numbered from 401 to 430, each room gives an earning of Rs. 4675/ day for the first 15 days a month and for the later half, Rs. 5370/ day per room. Find the average income room per day over the month of 30 days? A) 5700.5 B) 5872.7 C) 5900.5 D) 5022.5

Description : In a famous restaurant rooms were numbered from 401 to 430, each room gives an earning of Rs. 4675/ day for the first 15 days a month and for the later half, Rs. 5370/ day per room. Find the average income room per day over the month of 30 days? A) 5700.5 B) 5872.7 C) 5900.5 D) 5022.5  

Last Answer : Answer: D) Total number of rooms = 30 earning in 1st 15 days for 30 rooms  = 15 * 4675* 30 = Rs. 2103750 earning in 2nd 15 days for 30 rooms  = 15 * 5370 * 30 = Rs. 2416500 Average income per ... day over the month of 30 days  = [ 2103750 + 2416500] / [ 30 * 30]  = Rs. 5022.5

The average price of 12 note books is Rs.15 while the average price of 10 of these note books is Rs.13. Of the remaining 2 note books, if the price of one note book is 50% more than the price of the other, what is the price of each of these two note books? A) Rs. 30, Rs.20 B) Rs. 8, Rs. 30 C) Rs. 10, Rs. 16 D) Rs. 12, Rs. 20

Description : The average price of 12 note books is Rs.15 while the average price of 10 of these note books is Rs.13. Of the remaining 2 note books, if the price of one note book is 50% more than the price of the other, what is the price of ... Rs. 30, Rs.20 B) Rs. 8, Rs. 30 C) Rs. 10, Rs. 16 D) Rs. 12, Rs. 20

Last Answer : Answer: A) Total price of 12 note books = Rs. 180  Total price of 10 note books= Rs. 130 ⇒ The price of 2 note books = Rs. 50 Let the price of each book be x and y. ⇒ x + y = 50 ----- ... note book is 50% more than the other price 150y/100+y=50  y=20 Substituting y value in (1) we get, x=30

The average age of four boys, five years ago was 9 of all the five is 15 years. The present age of the new boy is 1. 22 years 2. 24 years 3. 21 years 4. 18 years 5. 19 years

Description : The average age of four boys, five years ago was 9 of all the five is 15 years. The present age of the new boy is 1. 22 years 2. 24 years 3. 21 years 4. 18 years 5. 19 years

Last Answer : 5; Five years ago the average age of 4 boys = 9 years The present average age of 4 boys = 9+5 = 14 So the present age of new boys = 15 + 4 x 1 = 19 years

Average age of A, B, C is 90yrs, however when D joins them, then the average comes down to 80 yrs. Now a new person E, whose age is six-fifth of the age of D, replaces A and the new average is 78. What is age of A? A) 64 B) 68 C) 62 D) 66

Description : Average age of A, B, C is 90yrs, however when D joins them, then the average comes down to 80 yrs. Now a new person E, whose age is six-fifth of the age of D, replaces A and the new average is 78. What is age of A? A) 64 B) 68 C) 62 D) 66

Last Answer : B) according to the question A+B+C/3=90 => A+B+C =270…………..(1) A+B+C +D/4=80 => A+B+C +D=320………(2) From the equation 1 and 2 D=50 E =6/5×50=60 E+B+C +D/4=78 => E+B+C +D =312 B+C +D =312-60=252……………..(3) From 2and 3 The age of A=320-252=68

Students of two university appeared for a common test of maximum 60 marks. The average of their marks for university 1 & university 2 are 39 & 42 respectively. If the no of students of university 1 is twice the no of students of university 2. Then what is the average marks of all students of both the university? A) 40 B) 42 C) 26 D) 36

Description : Students of two university appeared for a common test of maximum 60 marks. The average of their marks for university 1 & university 2 are 39 & 42 respectively. If the no of students of university 1 is twice the no ... the average marks of all students of both the university? A) 40 B) 42 C) 26 D) 36

Last Answer : Answer: A) Let number of students of university2 be N and the no of students of university 1 be 2N the average of university1 and university 2 is 39 and 42 total marks of university 1 students and university 2 ... 78N and N*42 =42N average of both university,  =(78N+42N) /(N+2N) = 40 marks

15 years ago, vaishali age was 15 times the age of her brother and the sum of present ages of vaishali and brother is 94years. What will be the age of her brother after 18 years? a) 32 years b) 33.5 years c) 37 years d) 30 years

Description : 15 years ago, vaishali age was 15 times the age of her brother and the sum of present ages of vaishali and brother is 94years. What will be the age of her brother after 18 years? a) 32 years b) 33.5 years c) 37 years d) 30 years

Last Answer : C

18 friends went to a restaurant for taking their breakfast. 17 of them spent RS.24 each on their breakfast and the last one spent RS.16 more then the average expenditure of all the 18. What was the total money spent by them? A) 228 B) 448.9 C) 458.6 D) 428.0

Description : 18 friends went to a restaurant for taking their breakfast. 17 of them spent RS.24 each on their breakfast and the last one spent RS.16 more then the average expenditure of all the 18. What was the total money spent by them? A) 228 B) 448.9 C) 458.6 D) 428.0 

Last Answer : B)  Let the average expenditure of all the 18 be Rs ‘x’.  Then (24 * 17) + (x + 16) = 18x 424 + x = 18x x = 24.9 therefore total money spent 18x  = 18 * 24.9  = Rs.448.9

The mean of the ages of father and his son is 27 years. After 18 years, father will be twice as old as his son. Their present ages are (A) 42, 12 (B) 40, 14 (C) 30, 24 (D) 36, 18

Description : The mean of the ages of father and his son is 27 years. After 18 years, father will be twice as old as his son. Their present ages are (A) 42, 12 (B) 40, 14 (C) 30, 24 (D) 36, 18

Last Answer : Answer: A

The average age of the men in a team is 76 years and that of the women is 75 years. The average age for the whole team is. A) 75 yrs B) 75.5 yrs C) Cannot be computed with the given information D) None of the above

Description : The average age of the men in a team is 76 years and that of the women is 75 years. The average age for the whole team is. A) 75 yrs B) 75.5 yrs C) Cannot be computed with the given information D) None of the above

Last Answer : C) Clearly to find the average, we ought to number of men, women or total persons in the class, neither of which has been given. So the data provided is inadequate.

The average age of 10 members of a committee is the same as it was 4 years ago, because an old member has been replaced by ayoung member. Find how much younger is the new member?

Description : The average age of 10 members of a committee is the same as it was 4 years ago, because an old member has been replaced by ayoung member. Find how much younger is the new member?

Last Answer : Answer: 40 years.

The average age of the assembalage of people was 114 yrs. When the 2 people of the assembalage went out with age of age of 84 yrs and 108yrs, then the average of the assembalage increased by 12yrs. How many people are there initially? A) 3 B) 4 C) 5 D) 6

Description : The average age of the assembalage of people was 114 yrs. When the 2 people of the assembalage went out with age of age of 84 yrs and 108yrs, then the average of the assembalage increased by 12yrs. How many people are there initially? A) 3 B) 4 C) 5 D) 6 

Last Answer : Answer: C)  let the number of people initially be N total age of N people = 114N total age of N-2 people = 114N - ( 84+108) = 114N -192 average age of N-2 people = 126 = [ 114N - 192] / [ N - 2] N=5 Hence th required answer is 5

The average age of a morning class is 108, if the average age of 72 ladies in the class is as same as the total average and the number of gents in the class is 2 more than the ladies in the class, what is the average age of gents in the class? A) 152 B) 108 C) 156 D) 154

Description : The average age of a morning class is 108, if the average age of 72 ladies in the class is as same as the total average and the number of gents in the class is 2 more than the ladies in the class, what is the average age of gents in the class? A) 152 B) 108 C) 156 D) 154 

Last Answer : B) According to question, (72+74)X=72×108+74X 146x-74x=7776 72x=7776 X=7776/72= 108years

Monica's average expenses for 4 days is Rs 6.0. She spent Rs 7.70 on first day, Rs 6.30 on second day. If she spent 10 on third day , How much did she spend on the 4th day? (a) Rs 2 (b) Rs 3 (c) Rs 4 (d) Rs 0

Description : Monica's average expenses for 4 days is Rs 6.0. She spent Rs 7.70 on first day, Rs 6.30 on second day. If she spent 10 on third day , How much did she spend on the 4th day? (a) Rs 2 (b) Rs 3 (c) Rs 4 (d) Rs 0 

Last Answer : Rs 0 Hint : Required Amount = 24 - ( 7.70 + 6.30 + 10)

In an exam the average marks obtained by a candidate is 82 per paper. If he had obtained 32 marks more in science paper & 28more marks in social paper, then his average per paper is increased by 15 marks. Then how many papers when there in examination? A) 10 B) 6 C) 4 D) 8

Description : In an exam the average marks obtained by a candidate is 82 per paper. If he had obtained 32 marks more in science paper & 28more marks in social paper, then his average per paper is increased by 15 marks. Then how many papers when there in examination? A) 10 B) 6 C) 4 D) 8 

Last Answer : C)  let the number of paper be x total mark earned him = 82x then,, 82x+32+28= 97x 15x=60 x= 4 =number of subjects

There were 32 boys in a hostel. If the number of boys be increased by 15, then the expenditure on food increases by Rs. 43 per day while the average of expenditure of boys is reduced by Rs. 2. What was the initial expenditure on food per day? A) Rs.108.2 B) Rs.125.6 C) Rs.135.8 D) Rs.144.5

Description : There were 32 boys in a hostel. If the number of boys be increased by 15, then the expenditure on food increases by Rs. 43 per day while the average of expenditure of boys is reduced by Rs. 2. What was the initial expenditure on food per day? A) Rs.108.2 B) Rs.125.6 C) Rs.135.8 D) Rs.144.5

Last Answer : Answer: A)  Let initial expense of 32 boys = Rs. x average expense of 32 boys = x/32 average expense of 47 boys = (x + 43)/ 47 then, (x/32) - ((x+43)/47) = 2  x= Rs.108.28

The average of 35 results is 28. The average of first 17 of them is 24 and that of last 17 is 21. Find the 18th result? A) 125 B) 215 C) 512 D) 521

Description : The average of 35 results is 28. The average of first 17 of them is 24 and that of last 17 is 21. Find the 18th result? A) 125 B) 215 C) 512 D) 521

Last Answer : B) Clearly 18th result = (sum of 35 results)- (sum of 34 results) =(35 * 28) – { (17 *24) +(17 *21)} = 980 – (408 + 357 =980 – 765 =215

The average salary per head of all the employees in a company is Rs. 180. The average salary of 24 employees is Rs. 1040and the average salary per head of the rest is Rs. 160. Find the total number of employees in the workshop. A) 2841 B) 1056 C) 1195 D) 2145

Description : The average salary per head of all the employees in a company is Rs. 180. The average salary of 24 employees is Rs. 1040and the average salary per head of the rest is Rs. 160. Find the total number of employees in the workshop. A) 2841 B) 1056 C) 1195 D) 2145

Last Answer :  B) Average = Sum of observations/Number of observations Let the number of employees be x. Given, the average salary per head of all the employees in a company is Rs. 180 So, the sum of salary of all the employees in ... (x - 24) = 180x ⇒ 24960+ 160x - 3840 = 180x ⇒ 20x = 2112 ⇒ x = 1056

The average marks of a class of 90 students is 126. Out Of them, 4 scores zero, first 60 students scored an average of 116, next 24 scored an average of 118. What is the mark obtained by the remaining student in the class? A) 750 B) 862 C) 774 D) 875

Description : The average marks of a class of 90 students is 126. Out Of them, 4 scores zero, first 60 students scored an average of 116, next 24 scored an average of 118. What is the mark obtained by the remaining student in the class? A) 750 B) 862 C) 774 D) 875

Last Answer : C) According to the question, 90*126=(4*0)+(60*116)+(24*118)+2y 11340=6960+2832+2y 2y=1548 y=774

There are 50 compartments in a Chennai express carrying an average of 70 passengers per compartments. At least 24 passengers were sitting in each compartment, not any compartment has equal number of passengers, and any compartment does not exceed the number of average passengers expect 50th compartment. Find how many passengers can be accommodated in 50th compartment? A. 748 B. 705 C.739 D.cannot be determined

Description :  There are 50 compartments in a Chennai express carrying an average of 70 passengers per compartments. At least 24 passengers were sitting in each compartment, not any compartment has equal number of passengers, ... can be accommodated in 50th compartment? A. 748 B. 705 C.739 D.cannot be determined 

Last Answer : C) Total number of passengers in Chennai express = 50*70 = 3500 Total number of candidates from 1 to 49 compartments = 24+25+....+70 = (70*71)/2 +(23*24)/2 = 2761 number of passengers in 50th compartment = 3500 - 2761= 739