Question

The speed of a stream is 2 mph. A boat travels 20 miles upstream in the same time it takes to travel 40 miles downstream. What is the speed of the boat in still water?
The speed of the boat in still water is mph.
(Simplify your answer. Type an integer or a decimal.)

Answer 1

Answer:

The speed of a boat in still water is 6 miles per hour.

Step-by-step explanation:

t = $\frac{20}{s-2}$  (upstream)

t = $\frac{40}{s+2}$  (downstream)

$\frac{20}{s-2}$ = $\frac{40}{s+2}$

40 ( s - 2 ) = 20 ( s + 2 )

40s - 80 = 20s + 40

20s = 120

s = 6 mi / h

The speed of a boat in still water is 6 miles per hour.