Math
posted by Mandy on .
A boat crew rowed 20 miles downstream, with the current, in 2hours. The return trip upstream, against the current, covered the same distance, but took 5 hours. Dine the crew's rowing rate in still water and the rate of the current? Still water _ MPH and Current _ MPH.
I know I already posted this question I didn't realize that I left out a few things. oops sorry!

Letting V = the rowing speed and C = the current speed:
20/(V+C) = 2 and
20/(VC) = 5
Then, 2(V+C) = 5(VC)
From which we get V = 7C/3
Substituting,
20/(7C/3+C) = 2 from which
C = 3MPH and V = 7MPH