Q156
ArithmeticSpeed, Time & Distance
A boat running downstream covers 24km in 4 hours, while for covering the same distance upstream it takes 6 hours. What is the speed of the boat in still water?
- a.3·5 km/hr
- b.5·5 km/hr
- c.6 km/hr
- d.5 km/hr
Answer: (D) 5 km/hr
Downstream speed = 24 ÷ 4 = 6 km/hr and upstream speed = 24 ÷ 6 = 4 km/hr. The boat's speed in still water is their average, (6 + 4) ÷ 2 = 5 km/hr. 6 km/hr is the downstream speed.