SOLUTION: Hi I need help with this problem Daniel's boat will go 15 miles per hour in still water. If he can go 12 miles downstream in the same amount of time as it takes to go 9 miles u

Algebra ->  Probability-and-statistics -> SOLUTION: Hi I need help with this problem Daniel's boat will go 15 miles per hour in still water. If he can go 12 miles downstream in the same amount of time as it takes to go 9 miles u      Log On


   

Question 294837: Hi
I need help with this problem
Daniel's boat will go 15 miles per hour in still water. If he can go 12 miles downstream in the same amount of time as it takes to go 9 miles upstream, then what is the speed of the current?
thanks.
Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
(time) = (distance) / (rate)

12 / (15 + c) = 9 / (15 - c)

"cross" multiplying ___ 180 - 12c = 135 + 9c

45 = 21c