A boat takes 4 hours to travel from place a to b downstream and back from b to a upstream. If the distance from a to b is 10.5 km and the speed of the current is 9 km/h, then the speed of the boat in still water, in km/h is?
Answer & explanation
Correct answer: option 3
Let speed of boat = U km/hr.
ATQ,
\(\frac{10.5}{U + 9}\) + \(\frac{10.5}{U - 9}\) = 4
Go through option or solve it
U = 12 km/hr.