Description : A group of students of arithmetic mean of the marks in a test was 63. The brightest 30% of them secured a mean score of 70 and the dullest 15% a mean score of 41. The mean score of remaining 55 % is A) 63.675 B) 61.785 C) 65.181 D) 66.67
Last Answer : C) Let the requird mean score be ‘x’ Then (30*70)+(15*41)+55x = 63*100 2100+615+55x=6300 2715+55x=6300 55x=3585 X=65.181
Description : The average height of 60 girls was calculated to be 300 cm. It was detected later that one value of 330 cm was wrongly copied as 270 cm for the computation of the mean. Find the correct mean. A) 301cm B) 300.5cm C) 307cm D) 311cm
Last Answer : A) Calculated average height of 60 girls = 300cm. Incorrect sum of the heights of 60 girls = (300 60)cm = 18000 cm. Correct sum of the heights of 60 girls = (incorrect sum) - (wrongly copied item) ... 330) cm = 18060cm. Correct mean = correct sum/number of girls = (18060/60) cm = 301 cm.
Description : When a girl weighing 90 kgs left a class, the average weight of the remaining 119 students increased by 400 g. What is the average weight of the remaining 119 students? A) 124 B) 138 C) 145 D) 116
Last Answer : B Let the average weight of the 119 students be X. Therefore, the total weight of the 119 of them will be 119X. The questions states that when the weight of this student who left is added, the total ... , the average weight decreases by 0.4 kgs. (119X+90)/120=X−0.4 ⇒119X+90=120X−48 ⇒X=138
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
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
Description : In an competitive examination, the average was found to be 72 marks. After detecting the errors the marks of 94 candidates had to be charged from 90 to 66 each, and the average is reduced to 64 marks. Find the total number of candidates who took the exam. A) 282 B) 382 C) 828 D) 200
Last Answer : A) let the number of candidates be A total marks of candidates = 72A after detecting error the change of marks for one candidate = 90 - 66 = 24 marks change of marks for 94 candidates = 94*24 = ... after detecting error of N candidates = 64A then, 72A- 2256= 64A , 8A=2256 A=282
Description : The least number that is divisible by all the numbers from 1 to 5 is: (a) 70 (b) 60 (c) 80 (d) 90
Last Answer : (b) 60
Description : The average weight of M,N and O is 168 kg. If P joins the group, the average weight of the group becomes 160 kg. If another man Q who weighs 6kg more than P replaces M, then the average of N,O,P and Qbecomes158 kg. What is the weight of M? A) 175 B) 140 C) 145 D) 150
Last Answer : D) M+N+O =168 * 3 =504 M+N+O+P=160*4=640……(1) P=136 kg and Q =142 kg N+O+P+Q =158*4 =632 N+O+P =632-142 =490…..(2) from 1 & 2, M=640-490 =150kg
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
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
Description : In a post graduate examination the marks obtained by a student is 75 per paper. If he had obtained 33 marks more in Evs paper & 27 more marks in science paper, then his average per paper is increased by 3 marks. Then how many papers were there in exam? A) 10 B) 12 C) 14 D) 20
Last Answer : Answer: D) Let the number of paper be A. Then total marks earned him = 75A from questions, 75A + 33+ 27= 78A 3A = 60=> A=20 = number of subjects
Description : The average score in a bank examination of 13 students of a class is 50. If the scores of the top five students are not considered, the average score of the remaining students falls by 5. The pass mark ... integral scores, the maximum possible score of the topper is. A) 85 B) 90 C) 95 D) 100
Last Answer : D Average = Sum of observations/Number of observations Given, average score in a bank examination of 13 students of a class is 50. Sum of total scores = 13 50= 650 Given, if the scores of the top five students are not ... b + c + d + e = 290 ⇒46+ 47 + 48+ 49 +e = 290 ⇒e = 100
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
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)
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
Description : The average age of 150 students in a class is 40% of the number of students in the class and the average age of a group of 50 students present in the class is 32yrs and the average age of another 50 students ... is the average age of the remaining students in the class? A) 102 B) 118 C) 112 D) 108
Last Answer : C) 150 students average 150×40/100=60 years According to the question, 150×60=50×32+50×36+50×X 50×X=9000-1600-1800 50x=5600 X=112
Description : 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 ... average marks scored by the 8 students who moved is 150 A) 25 B) 30 C) 35 D) 40
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
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
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
Description : There are five numbers, the second number is 25% more than the first or third number, the 4th number is 5/4 of the third number and the fifth number is 3/2of the 3rd number. What is the average of 5 numbers if the first number is 10? A) 12.5 B) 12 C) 13 D) 10
Last Answer : B) Let us consider 5 numbers are A,B,C,D and E B=125/100×A B=125/100×C 125/100×A=125/100×C A/C=1/1 D=5/4×c E=3/2*C First number is 10, A=10=x B=25% ×10+10=12.5 C=10 D=5/4×10=12.5 E=3/2×C=15 Required average=10+12.5+10+12.5+15/5=12
Description : An Aided school has only three classes which contain 70, 36 and 40students respectively. The pass percentage of these classes are30,25 and 20 respectively. The pass percentage of the aided school is A) 23 % B) 15% C) 26 % D) 30%
Last Answer : C) Total number of students passed in class1 = 30/100 *70 = 21 Total number of students passed in class 2= 25/100 *36 = 9 Total number of students passed in class 3= 20/100 *40 = 8 Total number of students passed in the school = 38 Thus, pass percentage of the school = 38 /146*100 = 26 %
Description : If the average of two numbers are 138& product is 2241. Then find the difference of both numbers? A) 225.40 B) 259.25 C) 267.81 D) 294.57
Last Answer : B) let the two number be a & b sum of two numbers, a+b = 138*2 =276---1 product of two numbers, a*b=2241 (a+b)2 = a2 + 2ab + b2 ------2 (a-b)2 = a2 -2ab +b2 ------3 solving 2 & 3, 76176 - (a-b)2 = 4*2241 a-b = 259.25
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
Description : The batting average for 20 innings of a cricketer is 25 runs. His highest score exceeds his lowest score by 86 runs. If these two innings are excluded, the average of the remaining 18 innings is 22runs. Find out the highest score of the player. A) 85 B) 90 C) 95 D) 100
Last Answer : C) Total runs scored by the player in 20 innings = 20*25 Total runs scored by the player in 18 innings after excluding two innings = 18 22 Sum of the scores of the excluded innings = 20 25 - 18 22 = 104 Given that ... Now x + 86 + x = 104 => 2x = 18 then x = 9 Highest score = 9+ 86 = 95
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
Description : What is the intensity of sound in normal conversation? (a) 10-20 dB (b) 30-60 dB (c) 70-90 dB (d) 120-150 dB
Last Answer : b) 30-60 dB
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
Description : The average weight of a group of 22students is 34kg. When the weight of the staff is also included, the average weight increases by 2kg. What is the weight of the staff? A. 80 kgs B. 54 kgs C. 47 kgs D. 33kgs
Last Answer : A) The average weight of a group of 22students = 34 kgs. Therefore, the total weight of the group = 22*34 = 748 kg When the weight of the staff is included, there are 23 individuals. The average ... , the total weight of the 22 students plus the staff = 23* 36= 828 828-748=80 kg.
Description : A students maks were wrongly entered as 72 instead of 52. Due to that the average marks for the class got increased by half. The number of students in the class is. A) 50 B) 56 C) 46 D) 40
Last Answer : D) Let there be y students in the class Total increase in marks = y *1/2 = y/2 Therefore y/2 = (72 – 52) y/2 = 20 y = 40
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
Description : 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
Last Answer : C Let the number of passed students be x. Then total marks = 60 × 18= 20x + (60– x) × 8 1080= 20x + 480– 8x 12x = 600 ∴ x = 50 ∴ number of passed students = 50
Description : Of the 5 numbers, the first is twice the second, the second is one – third of the third, the third is 5 times of the fourth, and the fourth is three – seventh of fifth. The average of the numbers is 35. The largest of these number is. A) 30.63 B) 65.625 C) 43.75 D) 75.356
Last Answer : B) Let the fifth number be x'. 4th number = 3/7 x 3rd number = 5 (3/7 x) = 15/7x 2nd number = 1/3 (15/7 x) = 15 /21 x 1st number = 2 (15/21 x) = 30/21 x X + 3/7 x + 15 /7 ... 120x = 3675 X = 30.625 So the numbers are 30.62, 13.125, 65.625, 21.875, 43.75. Therefore largest number is 65.625.
Description : The average of a positive numbers (non-zero) and its square is 8 times the number. The number is A) 15 B) 17 C) 13 D) 19
Last Answer : A) Let the number be ‘x’ rThen x+x^2/2 = 8x X+x^2=16x X^2=15x X^2 – 15x = 0 X(x-15)=0 X=0 or x= 15 So the number is 15 (because given [non-zero] positive).
Description : Calculate the prime cost from the following information: Direct material purchased: Rs. 1,00,000 Direct material consumed: Rs. 90,000 Direct labour: Rs. 60,000 Direct expenses: Rs. 20,000 Manufacturing overheads: Rs. 30,000 (a) Rs. 1,80,000 (b) Rs. 2,00,000 (c) Rs. 1,70,000 (d) Rs. 2,10,000
Last Answer : (c) Rs. 1,70,000
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
Description : The average of 5 numbers is 9 and the average of the last three numbers is 5.Find the average of the first two numbers.
Last Answer : Sum of 5 numbers = 9 x 5 = 45 Sum of last three numbers = 15 The average of 1st two numbers = 45-15/2 = 30/2 = 15.
Description : The average of 7 consecutive odd numbers is 41. Find the largest of these numbers A) 40 B) 57 C) 47 D) 43
Last Answer : C) Let the numbers be x , x+2,x+4,x+6, x+8, x+10 and x+12 Then x+x+2+x+4+x+6+x+8+x+10+x+12/7 7x+42=287 7x=245 X=35 Largest number = x+12 = 35+12 =47
Description : Find the average of first 85 natural numbers? A) 43 B) 41 C) 45 D) 47
Last Answer : A) Sum of 1st n natural numbers = n(n+1)/2 So, sum of 1st 85 natural numbers = 85(85+1)/2 =85(86)/2 =7310/2 =3655 Required average = 3655/85 =43.
Description : Find the average of even numbers above 1000 & upto 1 lakh? A) 50500 B) 50000 C) 49500 D) 51500
Last Answer : Answer: A) No of even numbers upto 1lkah = 50000 No of even numbers upto 1000 = 500 No of even numbers above 1000& upto 1 lakh= 49500 sum of first N even numbers = N*N sum ... - 500*500 = 2499750000 average of even numbers above 1000& upto 1 lakh = 2499750000/ 49500 = 50500
Description : Octane number of petrol normally used in petrol engines is of the order of a. 20-30 b. 40-60 c. 60-70 d. 80-90
Last Answer : ANSWER d. 80-90
Description : Octane number (unleaded) of reformed gasoline may be upto (A) 60 (B) 70 (C) 80 (D) 90
Last Answer : (D) 90
Description : The number of heart beats on an average in an adult human is in the range of (1) 60-65 (2) 66-70 (3) 71-80 (4) 85-90
Last Answer : 71-80
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
Description : 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
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.
Description : 11 girls went to a canteen. 10 of them spent 10 each and the 11th girl spent 25 more than the average expenditure of all. Find the total money spent by them? A) 172 .5 B) 178 .5 C) 137.5 D) 165.5
Last Answer : C) Let the average money spent by the 11girls = x Money spent by the 11th girl = (x + 25) Money spent by the other 10 girls = (10*10) = 100 Total money spent by the 11 girls = (100 + x + 25) =(x + ... = (x + 125)/ 11 =>10x=125 x =12.5 Total money spent by the 11 girls = 11*12.5 = 137.5.
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
Description : In plain sedimentation tanks under normal conditions, impurities are removed upto (A) 60 % (B) 70 % (C) 80 % (D) 90 %
Last Answer : (B) 70 %
Description : amount of liquid that a man can spray in a day is: A. 60 litres liquid B. 70 litres liquid C. 80 litres liquid D. 90 litres liquid
Last Answer : 90 litres liquid
Description : Standerd disc plough consist of steel dics of… to……. CM diameter. a. 60,90 c) 60,80 b. 70,100. d) 70,90
Last Answer : 60,90
Description : To dry fruits out-of-doors, humidity below ____ percent is best. a. 60 c. 80 b. 70 d. 90
Last Answer : a. 60