A started a journey at 1:00 p.m. at a speed of 40 km/h. B started from the same spot and in the same direction at 1:40 p.m. at a speed of 50 km/h. How many minutes will B take to catch up with A?

Correct option is D

Given:

Speed of A = 40 km/h

Speed of B = 50 km/h

B starts 40 minutes after A

Formula Used:

Time = distance ÷ speed

Solution:

Lead distance by A = $$40 \times \frac{40}{60} = \frac{80}{3}\ \text{km}$$​​

Relative speed = 50 – 40 = 10 km/h

Time to catch up = $$\frac{80}{3} \div 10 = \frac{8}{3}\ \text{hours} = \frac{8}{3} \times 60 = 160\ \text{minutes}$$​​