Question

A motor boat covers the distance between two places on a river and returns in $14hrs$. If the velocity of the boat in still water is $35km/h$ and velocity of water in the river is $5km/h$, then the distance between the two places is

• A. $100km$
• B. $240km$
• C. $220km$
• D. $180km$

Answer 1

Answer: (B)

$240km$

Speed downstream $=35+5=40km/hr$
Speed upstream $=35-5=30km/hr$
Let distance be $xkm$.

Then, total time $=14=\frac{x}{40}+\frac{x}{30}$
=> $x=240km$