Question

A theft was reported at 7 p.m. and the police started chasing at 9 p.m. In how much time will the police catch the thief if the speed of the police is 58 km/h and that of the thief is 40 km/h.
1. 80/9 hrs
2. 48/9 hrs
3. 40/9 hrs
4. 96/9 hrs

Answer 1

Correct Answer - Option 3 : 40/9 hrs

Given:

Theft time = 7 p.m.

Chase start time = 9 p.m.

Police's speed = 58 km/h

Thief's speed = 40 km/h

Concept:

Relative speed when moving in the same direction is the difference between individual speeds.

Formula used:

Speed = Distance/time

Calculation:

Thief is ahead by = 2 × 40 = 80 km

Relative speed = 58 - 40 = 18 km/h

Time taken to catch = 80/18 = 40/9 hours

∴ The time is 40/9 hrs.