model 7 average on ages/weight Section-Wise Topic Notes With Detailed Explanation And Example Questions

Question : 1

5 years ago, the average age of A, B, C and D was 45 years. With E joining them now, the average age of all the five is 49 years. How old is E ?

a) 40 years

b) 25 years

c) 64 years

d) 45 years

Question : 2

Out of 10 teachers of a school, one teacher retires and at his place a new teacher of age 25 years joins. As a result of it, the average age of the teachers is reduced by 3 years. The age of the retired teacher is

a) 58 years

b) 60 years

c) 55 years

d) 56 years

Question : 3

The average age of a husband and a wife was 27 years when they married 4 years ago. The average age of the husband, the wife and a new-born child is 21 years now. The present age of the child is

a) 3 years

b) 4 years

c) 1 year

d) 2 years

Question : 4

The average age of 20 boys in a class is 12 years. 5 new boys are admitted to the class whose average age is 7 years. The average age of the boys in the class becomes

a) 9.5 years

b) 8.2 years

c) 11 years

d) 12.5 years

Question : 5

In a class there are 30 boys and their average age is 17 years. On one boy aged 18 years leaving the class and another joining, the average age becomes 16.9 years. The age of new boy is

a) 11 years

b) 25 years

c) 15 years

d) 13 years

Question : 6

The average age of 40 students of a class is 18 years. When 20 new students are admitted to the same class, the average age of the students of the class is increased by 6 months. The average age of newly admitted student is

a) 19 years 6 months

b) 19 years

c) 20 years 6 months

d) 20 years