Numerical answer
A boat travels 30 km downstream in 2 hours and returns the same distance upstream in 3 hours. Find the speed of the boat in still water, in km/hr.
Show answer and solution
Answer: 12.5
Downstream speed = 30/2 = 15 km/hr. Upstream speed = 30/3 = 10 km/hr. Speed in still water = (downstream + upstream)/2 = (15+10)/2 = 12.5 km/hr. (Stream speed = (15−10)/2 = 2.5 km/hr.)
Saved on this device. Sign in or create a free account to keep it on every device.