A person rows upstream a distance of 55 km in 5 hours and rows downstream a distance of 75 km in 3 hours. How much time will he take to row a distance of 96 km in still water?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 5 hours 20 minutes
Let boat speed in still water = x km/h
Speed of stream = y km/h
Upstream speed = x - y = 55/5 = 11 km/h............(1
Downstream speed = x + y = 75/3 = 25 km/h...........(2
From equation 1 and equation 2
x = 18 km/h
y = 7 km/h
Now,
Time to row a distance of 96 km in still water = 96 /18 = 5 hours 20 minutes