A boatman goes 2 km against the current of the stream in 1 hour and goes 1 km along the current in 10 minutes. How long will it take to go 5 km in stationary water?
Q1. A boatman goes 2 km against the current of the stream in 1 hour and goes 1 km along the current in 10 minutes. How long will it take to go 5 km in stationary water?
Answer: 1 hr 15 min
Explanation: Upstream speed = 2 km/h; downstream = 1 km in 10 min = 6 km/h; still-water speed = (2+6)/2 = 4 km/h; time for 5 km = 5/4 h = 1 hour 15 minutes.