A man can row three-quarters of a kilometer against the stream in 11 ¼ minutes and return in 7 ½ minutes. The speed of the man in still water is________?
Q1. A man can row three-quarters of a kilometer against the stream in 11 ¼ minutes and return in 7 ½ minutes. The speed of the man in still water is________?
Answer: 5 km/hr
Explanation: Upstream speed = (3/4 km)/(11.25/60 h) = 4 km/h. Downstream = (3/4)/(7.5/60) = 6 km/h. Still-water speed = (4+6)/2 = 5 km/h.