A boatman rows 16 km downstream in 2 hours and covers the same distance upstream in 4 hours. Find the speed of the boat in still water. MCQ with Answer and Explanation

Explanation:
Average Speed = 2xy / (x + y) = (2 * 50 * 40) / (50 + 40) = 4000 / 90 = 44.44 km/h.

Explanation:
Radius r = 35 cm = 0.35 meters. Circumference = 2 * (22/7) * 0.35 = 2.2 meters. Distance covered in 1 minute = 400 * 2.2 = 880 meters. Distance covered in 1 hour = 880 * 60 = 52800 meters = 52.8 km. Speed = 52.8 km/h.

Explanation:
Time difference = 10 - 2 = 8 minutes = 8/60 hour = 2/15 hour. Let distance be d. d/5 - d/6 = 2/15 => d/30 = 2/15 => d = 60/15 = 4 km.