Question: Eleven years earlier, the average age of a family of 4 members was 28 yr. Now the age of the same family with six members is yet the same, even when 2 children were born in this period. If they belong to the same parents and the age of the first child at the time of the birth of the younger child was same as there were total family members just after the birth of the youngest members of this family, then the present age of the youngest member of the family is
Options:
A) 3 yr
B) 5 yr
C) 6 yr
D) None of these
Show Answer
Answer:
Correct Answer: A
Solution:
- Number of family members Average Total
Eleven years 4 28 112
Presently if 4 29 156
6 28 168
Since, it is obvious that just after the birth of the youngest member (i.e. child), there were 6 family members in the family, therefore at the time of birth of the youngest child, the elder child’s age was 6 yr,
Now, the sum of their age $ =x+(x+6)-12 $
$ =(168-156) $
$ \Rightarrow $ $ 2x-6=12 $
$ \Rightarrow $ $ x=9 $
$ \therefore $ Present age of the youngest member $ =9-6=3yr $
BETA
