Question

A thief steals a necklace at 12.05 a.m. and runs at the speed of 25 km/hr. Police starts chasing the thief at 12.20 a.m. at the speed of 45 km/hr. At what time will the thief be caught?

1. 12:38:45 a.m.
2. 12:38:30 a.m.
3. 12:39:15 a.m.
4. 12:39:45 a.m.
5. None of these

Answer 1

Correct Answer - Option 1 : 12:38:45 a.m.

Given:-

Speed of thief, t = 25 km/hr

Speed of police, p = 45 km/hr

Concept and Formula:-

Relative speed when two person are moving in same direction.

Relative speed = p – t

Distance = speed × time

Calculation:-

Distance travelled by thief before police starts chasing = 25 × (15/60) (12.05 a.m to 12.20 a.m.) = 6.25 km

Time for catching = 6.25/(45 – 25) = 0.3125 hours = 18.75 minutes = 18 minutes 45 seconds.

Time at which thief is caught = 12.20 a.m. + 18 minutes 45 seconds = 12:38:45