A thief runs away from A with a speed of 20 km/hr. A police from a station 60 km away started chasing him after 1 hr. with a speed of 40 km/hr. Time taken by the police to catch the thief is :
Choose the correct choice from the following answers:
A) 4 hrs
B) 4.5 hrs
C) 5.4 hrs
D) 6 hrs .
E) none of these

Rationale: explanation : solution : distance traveled by the thief in 1 hr . = 20 km . total distance of them after 1 hr = ( 60 + 20 ) km = 80 km . their relative speed = ( 40 - 20 ) = 20 km / hr . time taken to catch the thief = 80 / 20 = 4 hrs . answer : a
Answer: A