A boat goes 1 km downstream in 7\(\frac{1}{2}\) minutes and goes 5 km against the stream in one hour. Find the velocity of the boat in still water.
Answer & explanation
Correct answer: option 2
ATQ,
(D.S) Downstream speed = \(\frac{1}{7\frac{1}{2}}\) x 60 = 8 km/hr
(U.S) Upstream speed = \(\frac{5}{1}\) = 5 km/hr
Velocity of boat = \(\frac{D.S + U.S}{2}\) = \(\frac{8 + 5}{2}\) = 6\(\frac{1}{2}\) km/hr