One day last summer, Jim went kayaking on the Little Susitna River in Alaska. Paddling upstream against the current, he traveled 45 miles in 5 hours. Then he turned around and paddled twice as fast downstream and, with the help of the current, traveled 27 miles in 1 hour. Find the rate of the current.
A)3 mph
B)27 mph
C)12 mph
D)15 mph
E)9 mph

Question

Quizplus · Accepted Answer

The rate of the current can be found by setting up equations based on the information given. Let $x$ be Jim's kayaking speed in still water and $y$ be the speed of the current. When paddling upstream, his effective speed is $x - y$, and when paddling downstream, it's $x + y$. From the information given: $45 = 5(x - y)$ and $27 = 1(2x + 2y)$. Solving these equations simultaneously gives $x = 12$ mph and $y = 3$ mph.

One Day Last Summer, Jim Went Kayaking on the Little