arithmetic - a person can row 60 km downstream in 5 hr if the speed of the current is 5 kmhr then find in what time will be able to cover 8 km upstream - skillgun

Speed of the person downstream = 60/5 = 12 km/hr
Speed of current = 5 km/hr
Let the person takes t hours to cover 8 km upstream.
Then, speed of the current = (1/2)/ (Downstream Speed - Upstream Speed)
=> 5 = (1/2) (12 - 8/t)
=> t = 4 hours