A boat can travel with a speed of 13 km/hr in still water . If the speed of stream is 4 km /hr in the same direction , time taken by boat to go 63 km in opposite direction is

Options

A. 7 hours
B. 9 hours
C. `3 9/17` hours
D. 4 hours

Answer

A

Explanation

अभीष्ट समय ` = (63)/(13-4) = 63/9 = 7hr. `