SOLUTION: A boat travels between tho towns along a river. It travels 18 km upstream and back in a total time of 2 hours 10 minutes. Find the difference of the time taken to travel upstream a

Algebra ->  Rate-of-work-word-problems -> SOLUTION: A boat travels between tho towns along a river. It travels 18 km upstream and back in a total time of 2 hours 10 minutes. Find the difference of the time taken to travel upstream a      Log On


   

Question 1006499: A boat travels between tho towns along a river. It travels 18 km upstream and back in a total time of 2 hours 10 minutes. Find the difference of the time taken to travel upstream and downstream.
Answer by josgarithmetic(39613) About Me  (Show Source):
You can put this solution on YOUR website!
            rate          time          distance
up          r-c           18/(r-c)         18
down        r+c           18/(r+c)         18
Total                     2%2B1%2F6


Time difference is 18%2F%28r-c%29-18%2F%28r%2Bc%29.

Time sum 18%2F%28r-c%29%2B18%2F%28r%2Bc%29=2%261%2F6


Average round trip:
%28%28r-c%29%2B%28r%2Bc%29%29%2F2=36%2F%282%261%2F6%29
Simplify this, and you can have the boat rate for still water (without river current).