Problema Solution

A kayaker paddles upstream from camp to photograph a waterfall and returns. The kayakers speed while traveling upstream is 4mi/h and downstream is 7mi/h. What is the kayakers speed in still water? What is the speed of the current?

Answer provided by our tutors

let


v = the kayakers speed in still water

c = the speed of the current


the kayakers speed while traveling upstream is 4mi/h


v - c = 4


the kayakers speed while traveling downstream is 7mi/h


v + c = 7


by solving the system of equations


v - c = 4

v + c = 7


we find


v = 5.5 mi/h


c = 1.5 mi/h


the speed of the kayaker is 5.5 mi/h.

the speed of the current is 1.5 mi/h.