How long will a boy take to run round a square field of side 40 meters, if he runs at the rate of 12km/hr? Choose the most appropriate option.
A) 52 sec
B) 48 sec
C) 60 sec
D) 25 sec
E) 39 sec

Rationale: speed = 12 km / hr = 12 * 5 / 18 = 10 / 3 m / sec distance = 40 * 4 = 160 m time taken = 160 * 3 / 10 = 48 sec answer is b
Answer: B