Average Quantitative Aptitude Questions Page-3

17) Maria has taken 6 exams and her average marks so far are 89. If she gets 100, a perfect score on the remaining 2 exams. What will her new average be?
(A) 89.25
(B) 90.50
(C) 91.75
(D) 93.50

View Answer

Answer: Option C

Solution:
Marks of 6 exams = 89 * 6 = 534
Marks of all subjects = 534 + 100 + 100 = 734
Average of all exams = 734/8
= 91.75

18) The average age of husband, wife and their child 3 years ago was 27 years and that of wife and the child 5 years ago was 20 years. The present age of the husband is
(A) 40
(B) 35
(C) 45
(D) 55

View Answer

Answer: Option A

Solution:
Sum of the present ages of husband, wife and child = (27 * 3 + 3 * 3) years = 90 years
Sum of the present ages of wife and child = (20 * 2 + 5 * 2) years = 50 years
Husband's present age = (90 - 50) years = 40 years

19) A library has an average of 510 visitors on Sundays and 240 on other day. The average number of visitors in a month of 30 days starting with sunday is
(A) 280
(B) 285
(C) 290
(D) 295

View Answer

Answer: Option B

Solution:
As the month begin with sunday, so there will be five sundays in the month. So result will be:
= (
510*5 + 240*25/30
)
=
8550/30

= 285

20) What number must be added to 15, 18 and 22 to get an average of 20?
(A) 22
(B) 25
(C) 27
(D) 29

View Answer

Answer: Option B

Solution:
Let the number added be x
15 + 18 + 22 + x = 80
55 + x = 80
x = 80 - 55
= 25

21) The average height of five boys in a class is 19.994 inches. If the heights of four boys are 8.45, 14.70, 12.35, 18.28 inches, find the height of fifth boy:
(A) 55.79 inches
(B) 20.25 inches
(C) 49.19 inches
(D) 46.19 inches

View Answer

Answer: Option D

Solution:
Height of 5 boys => 19.994 * 5 = 99.97
Height of 4 boys = 8.45 + 14.70 + 12.35 + 18.28
= 53.78 inches
Height of 5th boy is 99.97 - 53.78 = 46.19 inches