A thief is noticed by a policeman from a distance of 300 m. The thief starts running and the policeman starts chasing him. The thief and policeman run at the rate of 11 km/h and 13 km/h, respectively. After running for how many kilometres will the policeman be able to catch the thief?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 1.95.
Concept used:
When two objects are moving in the same direction with speed S1 and S2
Relative speed = S1 - S2 (where S1 > S2)
Calculations:
Relative speed of policeman and thief = 13 - 11 = 2 km/h
Relative speed in (m/s) = 2 × 5/18 = 5/9 m/s
Required time taken = 300/(5/9) = 540 seconds
Distance travelled by the policman = 13 × (5/18) × 540 = 1.95 km