Word problems
The average runs scored by a batsman in 20 matches is 40. In the next 10 matches the batsman scored an average of 13 runs. Find his average in all the 30 matches?
31 29
28 30
Correct Answer: A. 31
Total score of the batsman in 20 matches = 800.
The total score of the batsman in the next 10 matches = 130.
The total score of the batsman in the 30 matches = 930.
Average score of the batsman = 930/30 = 31
The average amount with a group of seven numbers is Rs. 20. If the newly joined member has Rs. 50 with him, what was the average amount with the group before his joining the group?
A. Rs. 25
B. Rs. 18
C. Rs. 15
D. Rs. 22
Correct Answer: C. Rs. 15
Total members in the group = 7
Average amount = Rs. 20
Total amount with them = 7 * 20 = Rs. 140
One number has Rs. 50. So, the amount with remaining 6 people = 140 – 50 = Rs. 90
The average amount with them = 90/6 = Rs. 15
The sum of five numbers is 655.
The average of the first two numbers is 85 and the third number is 125. Find the average of the two numbers?
180
170
190
175
Correct Answer: A. 180
Let the five numbers be P, Q, R, S and T.
=>P+Q+R+S+T=655.
(P + Q)/2 = 85 and R = 125
P + Q = 170 and R = 125
P+Q+R=295
S+T=655–(P+Q+R)=360
Average of the last two numbers = (S + T)/2 = 180
Find the average of the series : 312, 162, 132, 142 and
122? A. 194
B. 174
C. 162
D. 186
Correct Answer: B. 174
Average = (312 + 162 + 132 + 142 + 122)/5 = 870/5 = 174
The average age of a group of 10 persons was decreased by 3 years when one person, whose
age was 42 years, was replaced by a new person. Find the age of the new person?
22
24
12
8
Correct Answer: C. 12
The initial average age of the 10 persons is P.
Age of the new person Q. Sum of the ages of the initial 10 persons = 10P
New average = (P-3) 10(P-3) = 10P – 42 + Q => Q = 12
The average of the marks of 12 students in a class is 36. If the marks of each student are doubled,
find the new average?
72
45
37
79
Correct Answer: A. 72
Sum of the marks for the 12 students = 12 * 36 = 432. The marks of each student are doubled,
the sum also will be doubled.
The new sum = 432 * 2 = 864. So, the new average = 864/12 = 72
The average of 10 numbers is 23. If each number is increased by 4, what will the new average
be? A. 22
B. 27
C. 25
D. 29
Correct Answer: B. 27
Sum of the 10 numbers = 230
If each number is increased by 4, the total increase =
4*10=40
The new sum = 230 + 40 = 270 The new average = 270/10 = 27
The average of 35 numbers is 25. If each number is multiplied by 5, find the new
average? A. 96
B. 125
C. 140
D. 168
Correct Answer: B. 125
Sum of the 35 numbers = 35 * 25 = 875
If each number is multiplied by 5, the sum also gets multiplied by 5 and the average also gets
multiplied by 5.
Thus, the new average = 25 * 5 = 125
The average marks of a class of 30 students is 40 and that of another class of 50 students is
60. Find the average marks of all the students?
50
47.5
59
52.5
Correct Answer: D. 52.5
Sum of the marks for the class of 30 students = 30 * 40 = 1200
Sum of the marks for the class of 50 students = 50 * 60 = 3000
Sum of the marks for the class of 80 students =
1200 + 3000 = 4200
Average marks of all the students = 4200/80 = 52.5
A batsman makes a score of 64 runs in the 16th innings and thus increased his average by 3.
Find his average after the 16th inning?
17
18
19
22
Correct Answer: C. 19
Let the average after the 16th inning be P.
So, the average after the 15th inning will be (P-3) Hence, 15(P-30) + 64 = 16P => P = 19
The average of 13 numbers is 60. Average of the first 7 of them is 57 and that of the last 7 is
61. Find the 8th number?
46
32
68
51
Correct Answer: A. 46
Sum of all the 13 numbers = 13 * 60 = 780
Sum of the first 7 of them = 7 * 57 = 399
Sum of the last 7 of them = 7 * 61 = 427
So, the 8th number = 427 + 399 – 780 = 46
Find the average of the first 20 natural
numbers? A. 10
B. 11.5
C. 12
D. 10.5
Correct Answer: D. 10.5
Average of the first ‘n’ natural numbers = (n + 1)/2
We get (20 + 1)/2 = 10.5
The average of 11 results is 50, if the average of first six results is 49 and that of the last six is
52. Find the sixth result?
46
56
34
57
Correct Answer: B. 56
1 to 11 = 11 * 50 = 550
1 to 6 = 6 * 49 = 294
6 to 11 = 6 * 52 = 312
6th = 294 + 312 – 550 = 56
The average of five results is 46 and that of the first four is 45. The fifth result
is: A. 1
B. 10
C. 12.5
D. 50
Correct Answer: D. 50
5*46–4*45=50
Three years ago the average age of a family of six members was 19 years. A boy have been
born, the average age of the family is the same today. What is the age of the boy?
A. 1 year
B. 1.5 years
C. 2 years
D. 2.5 year
Correct Answer: A. 1 year
6*22=132
7*19=133
—————–
133 -132 = 1 Year
Nine men went to a hotel. Eight of them spent Rs.3 each over their meals and the ninth spent Rs.2 more than the average expenditure of all the nine. Determine the total money spent by them?
Rs.29.25
Rs.30.25
Rs.32
Rs.35
Correct Answer: A. Rs.29.25
Average of 9 = x
9x = 8 * 3 + x * 2 x = 3.25
Total = 9 * 3.25 = 29.25
The average age 9 members of a committee are the same as it was 2 years ago, because an old number has been replaced by a younger number. Find how much younger is the new member than the old number?
A. 7 years
B. 11 years
C. 18 years
D. 27 years
Correct Answer: C. 18 years
9 * 2 = 18 years
A batsman in his 17th innings makes a score of 85 and their by increasing his average by 3.
What is his average after the 17th innings?
34
35
36
37
Correct Answer: D. 37
16x + 85 = 17 (x + 3)
x = 34 + 3 = 37
The average age of M boys is ‘b’ years and of ‘n’ girls ‘c’ years. The average age of all together
is:
A. (mb – nc)/ (m + n) years
B. (mb + nc)/ (m – n) years
C. (mb + nc)/ (m + n) years
D. (mb – nc)/ (m – n) years
Correct Answer: C. (mb + nc)/ (m + n) years
A team of eight entered for a shooting competition. The best marks man scored 85 points. If
he had scored 92 points, the average scores for. The team would have been 84. How many points altogether did the team score?
625
665
632
656
Correct Answer: B. 665
8*84=672–7=665
The average salary of workers in an industry is Rs.200 the average salary of technicians
being Rs.400 and that of non-technicians being Rs.125. What is the total number of workers?
250
275
550
400
Correct Answer: C. 550
The average age of 8 men increases by 2 years when two women are included in place of two
men of ages 20 and 24 years. Find the average age of the women?
A. 36 years
B. 24 years
C. 30 years
D. 18 years
Correct Answer: C. 30 years
20+24+8*2=60/2=30
The average of first five prime numbers greater than 20
is: A. 31.00
B. 31.01
C. 32.00
D. 32.2
Correct Answer: D. 32.2
Detail About MCQs+
23+29+31+37+41=161/5=32.2
The average of 9 observations was 9, that of the 1st of 5 being 10 and that of the last 5 being
8. What was the 5th observation?
6
7
8
9
Correct Answer: D. 9
1 to 9 = 9 * 9 = 81
1 to 5 = 5 * 10 = 50
5 to 9 = 5 * 8 = 40
5th = 50 + 40 = 90 – 81 = 9
The average of 1st 3 of 4 numbers is 16 and of the last 3 are 15. If the sum of the first and the
last number is 13. What is the last numbers?
8
6
5
2
Correct Answer: C. 5
A+B+C=48
B+C+D=45
A+D=13
A–D=3
A+D=13
2D=10
D = 5
The average age of three boys is 15 years and their ages are in proportion 3:5:7. What is the age
in years of the youngest boy?
9
15
18
21
Correct Answer: A. 9
3x + 5x + 7x = 45
=3
3x = 9
The average of first 10 odd numbers
is: A. 11
B. 10
C. 12
D. 17
Correct Answer: B. 10
Sum of 10 odd no. = 100
Average = 100/10 = 10
The average of first 10 natural numbers
is: A. 5
B. 5.5
C. 6.5
D. 6
Correct Answer: B. 5.5
Sum of 10 natural no. = 110/2 = 55
Average = 55/10 = 5.5
The average of first ten prime numbers which are odd
is: A. 12.9
B. 13.8
C. 15.8
D. 17
Correct Answer: C. 15.8
3,5,7,11,13,17,19,23,29,31
Average = 3+5+7+11+13+17+19+23+29+31/10
158/10
15.8
The average of 11 numbers is 10.9. If the average of first six is 10.5 and that of the last six is
11.4 the sixth number is:
11.0
11.3
11.4
11.5
Correct Answer: D. 11.5
Sum of 11 numbers = 11×10.9 = 119.9
Sum of 1st 6 numbers = 6×10.5 = 63
So, sum of last 5 numbers = 119.9-63 = 56.9
And sum of last 6 numbers = 6×11.4 = 68.4
Hence sixth number will be = 68.4-56.9= 11.5
The average of first 10 even numbers
is: A. 18
B. 22
C. 9
D. 11
Correct Answer: D. 11
Two automobiles are 150 kilometers apart and traveling toward each other. One automobile
is moving at 60km/h and the other is moving at 40km/h mph. In how many hours will they meet?
2.5
2.0
1.75
1.5
Correct Answer: D. 1.5
One moves at 60km/h, so in an hour, he’ll travel 60km
The other moves at 40km/h, so in an hour, he’ll travel 40km
This is towards each other, so, in an hour, we can say that they’ll get 60+40=100km closer.
This means that they get closer at 100km/h
Given that we have a distance of 150km, and the speed of closure at 100kmh, we can now use
the equation
S=D/T
Rearrange to find T (times both sides by T)
S x T = D (now divide both sides by S)
T=D/S
Time = 150km divided by 100km/h
Time = 1.5 hours
Or one hour and 30 minutes
If the average marks of three batches of 55, 60 and 45 students respectively is 50, 55, 60, then
the average marks of all the students is:
53.33
54.68
55
Correct Answer: B. 54.68
55 students get average marks of 55%.
so 55*50=2750
Similarly 60*55=3300
& 60*45=2700 now total no of marks obtain by all students of three batches= 2750+3300+2700=8750/= Total no of students= 55+60+45=160. By dividing total marks on each student, we get average marks obtain by each student so 8750/160 = 54.68
