A boat’s speed in still water is 22 km/h, while the river is flowing with a speed of 8 km/h and the time taken to cover a certain distance upstream is 4 hours more than the time taken to cover the same distance downstream. Find the distance.
Answer & explanation
Correct answer: option 1
We know that,
Upstream Speed = Speed of Boat – Speed of current
Downstream Speed = Speed of Boat + Speed of current
Given,
Difference in time = 4 hours
Still water speed = 22 km/h
Stream speed = 8 km /h
Upstream speed = ( 22 -8) = 14
Downstream speed = ( 22 +8) = 30
According to the given question ,
Now, let the required distance be D then,
\(\frac{D}{22 - 8}\) - \(\frac{D}{22 + 8}\) = 4
On solving,
16D = 420× 4
D = 105 km.