The age of P after 8 years is equal to the present age of Q and the present age of P is 8/9th of the present age of R and the average of the ages of Q and R after 4 years is 42 years. Find sum of the present age of P and the age of Q before 6 years.
a) 66 years
b) 60 years
c) 72 years
d) 45 years
e) None of these
Sol:
P = 8/9 * R = 8R/9
8R/9 + 8 = Q —- (1)
Q + 4 + R + 4 = 42 * 2
Q + R = 84 – 8
Q + R = 76 —- (2)
From (1) and (2),
8R/9 + 8 + R = 76
8R/9 + R = 68
(8R + 9R)/9 = 68
17R/9 = 68
R = 36 years
P = 8 * 36/9 = 32 years
Q + 36 = 76
Q = 40 years
Required sum = 32 + (40 – 6) = 32 + 34 = 66 years
