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

Question : 1

The average age of 8 persons is increased by 2 years, when one of them, whose age is 24 years is replaced by a new person. The age of the new person is :

a) 40 years

b) 42 years

c) 45 years

d) 38 years

Question : 2

3 years ago, the average age of a family of 5 members was 17 years. A baby having been born, the average age of the family is same today. The present age of the baby is

a) 1 $1/2$ year

b) 1 year

c) 3 years

d) 2 years

Question : 3

Five years ago, the average age of P and Q was 25. The average age of P, Q and R today is 25. Age of R after 5 years will be

a) 20 years

b) 15 years

c) 35 years

d) 40 years

Question : 4

If out of 10 selected students for an examination, 3 were of 20 years, age, 4 of 21 and 3 of 22 years, the average age of the group is

a) 21 years

b) 22 years

c) 20 years

d) 21.5 years

Question : 5

The present average age of a family of four members is 36 years. If the present age of the youngest member of the family be 12 years, the average age of the family at the birth of the youngest member was

a) 40 years

b) 48 years

c) 24 years

d) 32 years

Question : 6

From a class of 42 boys, a boy aged 10 years goes away and in his place, a new boy is admitted. If on account of this change, the average age of the boys in that class increases by 2 months, the age of the newcomer is :

a) 17 years

b) 19 years

c) 12 years 2 months

d) 10 years 6 months