-
The average age of two boys and their father is greater then average age of those two boys and their mother by 3 yr. The average age of the four is 19 yr. If the average age of the two boys be 51/2, then find the age of the father and mother.
-
- 37 yr and 28 yr
- 47 yr and 38 yr
- 50 yr and 41 yr
- 35 yr and 32 yr
Correct Option: A
Let the ages of mother, father and boys be M, F, B1 and B2, respectively.
The total age of four member
= 19 x 4
= 76 yr.
Given (B1 + B1)/2 = 11/2
⇒ B1 + B2 = 11
M + F + B1 + B2 = 76 - 11
⇒ M + F = 65 .......(i)
According to the question,
(B1 + B2 + F) / 3 = (B1 + B2 + M) / 3 + 3
⇒ B1 + B2 + F) = B1 + B2 + M + 9
⇒ F = M + 9
⇒ F - M = 9 ............. (ii)
From Eqs (i) and (ii), we get
F = 37 yr and M = 28 yr
