Question 1171616
Paddlewheel Pat has a motorboat.
 He can travel a distance of 10 miles boating into the current in the same time it takes him to travel 15 miles with the current.
 If the current has a speed of 3 mph, what is the speed of Pat’s boat in still water?
:
let s = his speed in still water
then
(s+3) = his speed with the current
and
(s-3) = his speed against
:
Write a time equation, time = dist/speed
{{{10/(s-3)}}} = {{{15/(s+3)}}}
cross multiply
15(s-3) = 10(s+3)
15s - 45 = 10x + 30
15s - 10s = 30 + 45
5s = 75
s = 75/5
s = 15 mph in still water
:
:
Check this by finding the time of each way, should be equal
15/18 = .833 hrs
10/12 = .833 hrs