Mahesh can row a certain distance upstream in 9 hours and downstream the same distance in 6 hours. If the speed of stream is 3 km/hr, then find the speed of Mahesh rowing in still water?
Answer & explanation
Correct answer: option 3
Upstream(U.S) : Downstream (D.S)
Time: 9 : 6
Time: 3 : 2
Speed: 2 : 3 (Inverse relation)
Speed of Boat : Speed of Stream= \(\frac{3\;+\;2}{2}\) : \(\frac{3\;-\;2}{2}\) = 5 : 1
Here,
1R = 3 km/hr (given)
Therefore, speed of Boat = 5 x 3 = 15 km/hr