Question

A boat travels 30 miles up the river in the same amount of time it takes to travel 38 miles down the same river. If the current is 2 miles per hour, what is the speed of the boat in still water?

Answer 1

x miles per hour  -   speed of the boat in still water
(x - 2)  -  speed up the river
(x + 2)  -  speed down the river

$\frac{30}{x - 2}$ = $\frac{38}{x + 2}$
30 * (x + 2) = 38 * (x - 2)
30x + 60 = 38x - 76
- 8x = - 136
x = 17 miles per hour  -  the speed of the boat in still water.