Question

A takes 3 hours more than B to walk 30 km. If A starts jogging at a speed twice his walking speed, he takes 2 hours less than B. Find the speed of A.

• A. 1 kmph
• B. 2 kmph
• C. 3 kmph
• D. 4 kmph
• E. 5 kmph

Answer 1

The correct option is C

3 kmph

$\text{Time taken by A}=\frac{30}{x}and\text{if A doubles his speed then time taken}=\frac{30}{2x}hrs\text{And time taken by B}=\frac{30}{2x}+2hrs\therefore \text{As per the problem,}\frac{30}{x}-3=\frac{30}{2x}+2\Rightarrow \frac{30}{x}-\frac{30}{2x}=5\Rightarrow \frac{60-30}{2x}=5\Rightarrow 60-30=10x\Rightarrow x=3\text{Time taken by B}=\frac{30}{3}-3=7hrs.\therefore SpeedofA=3km/hrandSpeedofB=\frac{30}{7}=4\frac{2}{7}km/hr.$