The speed of a boat in still water is 15 km/hr and the rate of current is 3 km/hr the distance travelled downstream in 12 minutes is :  Choose the correct choice from the following answers:
A) 2 km
B) 2.6 km
C) 3.6 km
D) 4 km
E) none

Rationale: sol . speed downstream = ( 15 + 3 ) kmph = 18 kmph . distance travelled = [ 18 * 12 / 60 ] km = 3.6 km . answer c
Answer: C