If 4 years ago the ratio between the ages of P and Q was 5 : 6 and the sum of their ages at present is 52, what is the ratio of their present ages ?

Answer: Option B

Let age of P = 5x
and age of Q = 6x
According to the question,
(5x + 4) + (6x + 4) = 52
11x = 44
x = 4
Present age of P = 5x + 4 = 5 × 4 + 4 = 24
Present age of Q = 6x + 4 = 6 × 4 + 4 = 28
$$\begin{array}{rl}& \therefore \text{Required ratio}\\ & \text{ = }\frac{24}{28}\\ & =\frac{6}{7}\\ & =6:7\end{array}$$