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

Question : 1

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 : 2

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 : 3

Average age of 6 sons of a family is 8 years. Average age of sons together with their parents is 22 years. If the father is older than the mother by 8 years, the age of mother (in years) is :

a) 52

b) 44

c) 68

d) 60

Question : 4

The average age of a family of 10 members is 20 years. If the age of the youngest member of the family is 10 years, then the average age of the members of the family just before the birth of the youngest member was approximately

a) 12.5 years

b) 27.14 years

c) 11$1/9$ years

d) 14.28 years

Question : 5

The average age of 30 boys in a class is 15 years. One boy, aged 20 years, left the class, but two new boys came in his place whose age differ by 5 years. If the average age of all the boys now in the class becomes 15 years, the age of the younger newcomer is :

a) 15 years

b) 20 years

c) 8 years

d) 10 years

Question : 6

There are 30 students in a class. The average age of first 10 students is 12.5 years. The average age of the remaining 20 students is 13.1 years. The average age (in years) of the students of the whole class is

a) 12.7 years

b) 12.5 years

c) 12.9 years

d) 12.8 years