The average of 3,8,7 and a is 6 and the average of 19,2,7, a and b is 11. What is the value of b? A) 11 B) 21 C) 31 D) 41

The average of 3,8,7 and a is 6 and the average of 19,2,7, a and b is 11. What is the value of b? A) 11 B) 21 C) 31 D) 41 
by

1 Answer

Answer :

B)

We have (3+8+7+a+6/5)=6

24 =a = 30

A=6

Also (19+2+7+a+b/5)=11

19+2+7+6+b=55

34+b=55

b=21


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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

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

The Cricketer average score in 40 over is 21, if the man scores 23runs in 8over, 26 runs in 10 over and 18runs in 14 over. What is the average score in remaining over? A) 18 B) 19 C) 16 D) 20

Description : The Cricketer average score in 40 over is 21, if the man scores 23runs in 8over, 26 runs in 10 over and 18runs in 14 over. What is the average score in remaining over? A) 18 B) 19 C) 16 D) 20 

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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

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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

The average height of 50 students in a class is 182 cm. 40 students whose average height is 182.5 cm left the class and 50 students whose average height is 180.5 cm joined the class. Find the average height of the present? A) 180.41 B) 175.5 C) 180.55 D) 185.5

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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

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In Wheat Crown root initiation stage comes —- days after sowing a. 21 b. 11 c. 31 d. 41

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A ship sails out to a mark at the rate of 10 km per hour and sails back at th rate of 15 km per hour. What is its average rate of sailing? (a) 10 km. p.h. (b) 12 km. p.h. (c) 15 km. p.h. (d) 11 km. p.h.

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If the average of 4 observations x, x+1, x+2, x+3 is 12 then the average of last 2 observations is A) 10 B) 11 C) 12 D) 13If the average of 4 observations x, x+1, x+2, x+3 is 12 then the average of last 2 observations is A) 10 B) 11 C) 12 D) 13

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The average height of a batch is 344 cm. 16more students with an average height of 320 cm joined the batch therefore decreasing the average height of the batch by 12 cm. Find the total strength of the batch? A) 12 B) 11 C) 14 D) 16

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Last Answer : Answer: D) let the initial strength of the batch be X total height of the batch initially = 344X total height of 16 new students = 320 * 16 = 5120 cm Then, the average height of X+ 16students = 332  332 = [5120 + 344 X]/ [X + 16]  X= 16 students

The average age of 11 daughters of a family is 12yrs. Average age of the daughters together with their parents is 27yrs. If mother is 14yrs younger than father. Then find the father's age A) 127 yrs B) 116.5 yrs C) 168yrs D) 170yrs

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The average state of the city in the first 4 days of a month was 116 degrees. The average for the second, third, fourth and fifth days was 120 degrees. If the state of the first and fifth days were in the ratio 7:8 then what is the state on the fifth day. A) 112degrees B) 128degrees C) 132degrees D) 130degrees

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Last Answer :  B)  Sum of states on 1st, 2nd, 3rd, 4th days = (116 *4) = 464 =======>A Sum of states on 2nd, 3rd, 4th and 5th days = (120 * 4)= 480 ======>b From a and b Subtracting each other ... be 7x and 8x degrees respectively Then 8x - 7x = 16 x = 16 therefore state on the 5th day = 8x = 128 degrees.

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

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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 mean of 8 article was found to be 15. On rechecking, it was found that two article were wrongly taken as 11 and 9 instead of 16 and 14 respectively. Find the correct mean. A) 17.25 B) 13.65 C) 16.54 D) 16.25

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Saravanan has scored an total of 90% in an examination with five subjects in the ratio 18:14:15:21:22. If 85% is the marks required to get an ‘A’ grade in each subject, then find in how many subjects did he get an ‘A’ grade. Given that the maximum marks in each subject is 120. A) 2 B) 3 C) 4 D) 5

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Last Answer : Answer: B) Maximum total marks = 5 120 = 600 Marks scored by Saravanan = 90/100*600=540 Let the marks scored by him in the 5 subjects be 18x,14x,15x,21x and 22x respectively. 18x + 14x + 15x + 21x + ... A' grade i.e. 0.85 120 = 102 Therefore, he has got an A' grade in 3 subjects.

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

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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

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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.

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Last Answer : i) Average value: The average value is defined as the average of all instantaneous values during one alternation . That is, the ratio of the sum of all considered instantaneous values to the ... as produced by the alternating current when flowing through the same resistance for the same time.

Average value

Description : Average value

Last Answer : Average value

Define average value.

Description : Define average value.

Last Answer : Average Value of Sinusoidal AC Waveform: The average value is defined as the arithmetical average or mean value of all the values of an alternating quantity over one cycle.  And/OR  For ... charge as is transferred by the alternating current during the same time under the same conditions. 

In the case of an unsymmetrical alternating current the average value must always be taken over?

Description : In the case of an unsymmetrical alternating current the average value must always be taken over?

Last Answer : In the case of an unsymmetrical alternating current the average value must always be taken over the whole cycle.

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 

A man spends Rs 1,800 per month on an average for the first four mouths and Rs 2,000 per month for the nest 8 months and saves Rs 5,600 a year. What is his average monthly income ?

Description : A man spends Rs 1,800 per month on an average for the first four mouths and Rs 2,000 per month for the nest 8 months and saves Rs 5,600 a year. What is his average monthly income ?

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The average of marks obtained by 60 students in a computer examination is 18. If the average marks of passed students is 20and that of the failed students is 8, what is the number of students who passed the examination? A) 100 B) 75 C) 50 D) 85

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The average marks scored by two Class A1 and A2 students are 120 and 130 respectively. If 8 students are moved from Class A2 to Class A1 and the average marks of the two Class get interchanged. Find the total number of students in two Class put together, if the average marks scored by the 8 students who moved is 150 A) 25 B) 30 C) 35 D) 40

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Last Answer :  D)  let the number of students in Class A1 be x and class A2 be y. Total marks scored by the students will be 120x and 130y, the average gets interchanged after moving student from y Thus we get, 130y- ... (x+8) 120x+1200=130x+1040 10x=160 X=16 Thus the total number of students =24+16=40

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

Insert the missing number in the following: 2/3, 4/7, ? , 11/21, 16/31 (A) 10/8 (B) 6/10 (C) 5/10 (D) 7/13

Description : Insert the missing number in the following: 2/3, 4/7, ? , 11/21, 16/31 (A) 10/8 (B) 6/10 (C) 5/10 (D) 7/13

Last Answer : Answer: D 2/3 = 2/2*2-1, 4/7 = 4/4 *2-1, 11/21 = 11/11*2-1, and 16/31 = 16/16*2-1; Therefore 7/13= 7/7*2-1.

In the sequence of numbers 2/3, 4/7, X, 11/21, 16/31 The missing number X is: (A) 8/10 (B) 6/10 (C) 5/10 (D) 7/13

Description : In the sequence of numbers 2/3, 4/7, X, 11/21, 16/31 The missing number X is: (A) 8/10 (B) 6/10 (C) 5/10 (D) 7/13

Last Answer : Answer: D

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 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.

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

Description : 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 

Last 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 - ... - e + f) = 5x Solving e - f = 30 years. Thus the difference of ages between replaced and new person = 30years.

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.

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