Practicing Success
A sailor takes thrice as much time as row to B from A against the current as he takes along the current to A from B. If he rows at the rate of 10 km/hr in still water, then what will be the rate of current? |
5 km/hr 15 km/hr 10 km/hr 20 km/hr |
5 km/hr |
If distance is same, then ratio of speed = \(\frac{1}{ratio\;of\;'time}\) Downstream(D.S) : Upstream(U.S) Time 1 : 3 speed 3 : 1 Then, ratio of speed of boat and current = \(\frac{3\;+\;1}{2}\) : \(\frac{3\;-\;1}{2}\) = 2 : 1 5x ⇓ ⇓ x5 (given) 10 km/hr 5 km/hr |