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

Question : 1

The average age of 24 boys and their teacher is 15 years. When the teacher’s age is excluded, the average age decreases by 1 year. The age of the teacher is

a) 39 years

b) 38 years

c) 41 years

d) 40 years

Question : 2

The average age of A and B is 20 years. If A is to be replaced by C, the average would be 19 years. The average age of C and A is 21 years. The ages of A, B and C in order (in years) are

a) 18, 20, 22

b) 18, 22, 20

c) 22, 20, 18

d) 22, 18, 20

Question : 3

The average age of a husband and his wife was 23 years at the beginning of their marriage. After five years they have a one-year old child. The average age of the family of three, when the child was born, was

a) 24 years

b) 23 years

c) 20 years

d) 18 years