The speed of the current in a stream is 3.3 mi/hr. It takes a canoeist 30 minutes longer to paddle 1.9 miles upstream than to paddle the same distance downstream. What is the canoeist's rate in still water? Round the answer to the nearest tenth of a mile per hour.
A)3.4 mi/hr
B)7.2 mi/hr
C)4.8 mi/hr
D)9.0 mi/hr
E)6.0 mi/hr

Question

Quizplus · Accepted Answer

The canoeist's rate in still water can be calculated using the formula for time: time = distance/speed. Let x be the rate in still water. The upstream speed is (x - 3.3) mi/hr and the downstream speed is (x + 3.3) mi/hr. The time difference is 0.5 hours. Solving the equation 1.9/(x - 3.3) = 1.9/(x + 3.3) + 0.5 gives x = 6.0 mi/hr.

The Speed of the Current in a Stream Is 3