Problema Solution

rowing with the current, a man in a canoe paddled 15 min in 3h. against the current, the man could paddle only 9 mi in the same amount of time. find the rate of the canoe in calm water and the rate of current.

Answer provided by our tutors

let


x = the rate of the canoe in calm water

c = the rate of the current

d1 = 15 mil

t = 3 h

d2 = 9 mi


15/(x + c) = 3


d2/(x - c) = 3


or


12/(x + c) = 3 => x + c = 4


9/(x - c) = 3 => x - c = 3


by solving the system of equations


x + c = 4

x - c = 3


we find


x = 3.5 miles/hour


c = 0.5 miles/hour


the rate of the canoe in calm water is 3.5 miles/hour.

the rate of the current is 0.5 miles/hour.