a boat is traveling in a river that is flowing downstream at a speed of 5 kilometers per hour.

Question

a boat is traveling in a river that is flowing downstream at a speed of 5 kilometers per hour. the boat can travel 30 kilomteters upstream in the same time it would take to travel40 kilograms downstream. what is the speed of the boat in still water

Answer 1

30 = (r-5)*t = rt - 5t

40 = (r+5)*t = rt + 5t

70 = 2rt

rt = 35

40 = 35 + 5t

5 = 5t

t = 1

which forces r=35

speed of boat is 35

35-5 = 30 miles per hour upstream

35+5 = 40 mph downstream

the speed of the boat is 35