A boat can travel with a speed of 13 km/hr in still water.if the speed of the stream is 4 km/hr, find the time taken by the boat to go 68 km downstream.
a) 2 hrs
b) 3 hrs
c) 4 hrs
d) 5 hrs
Correct option: c) 4 hrs
Explanation:
Speed downstream=(13+4) kmph =17 kmph
Time taken to travel 68 km downstream = (68/17) hrs = 4 hrs
