### The speed of A and B are in the ratio 3 : 4. A takes 20 minutes more than B to reach a destination. Time in which A reach the destination?

A. $1 \frac{1}{3}$ hours B. 2 hours C. $2 \frac{2}{3}$ hours D. $1 \frac{2}{3}$ hours Answer: Option A
Ratio of speed = 3 : 4 Ratio of time taken = 4 : 3 (As Speed $\frac{1}{\text { Time }}$ When distance taken remains constant.) Let time taken by A and B be 4x and 3x hour respectively. Then, $\begin{array}{l} 4 x-3 x=\frac{20}{60} \\ \text {Or, } x=\frac{1}{3} \end{array}$ Hence , time taken by A = 4x hours =$4 \times \frac{1}{3}=1 \frac{1}{3}$ hours.