1.  A thief is spotted by a policeman from a distance of 100 metres. When the policeman starts the chase, the thief also starts running. If the speed of the thief be 8 km/hr and that of the policeman 10 km/hr, how far the thief will have run before he is overtaken ?
A. 200 m
B. 400 m
C. 600 m
D. 300 m

Answer: Option B

Explanation:

Relative speed of the policeman = (10 - 8) km/hr
= 2 km/hr

Time taken by policeman to cover 100 m = (100/1000 X 1/2) hr
= 1/20 hr

In 1/20 hrs, the thief covers a distance of (8 X 1/20) km
= 2/5 km = 400 m.