SOLUTION: Callie took 20 min to drive her boat upstream to water ski at her favorite spot. Coming back at the same speed took her 15 min. If the current of the river is 5km, what was boat sp

Algebra ->  Customizable Word Problem Solvers  -> Travel -> SOLUTION: Callie took 20 min to drive her boat upstream to water ski at her favorite spot. Coming back at the same speed took her 15 min. If the current of the river is 5km, what was boat sp      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 900750: Callie took 20 min to drive her boat upstream to water ski at her favorite spot. Coming back at the same speed took her 15 min. If the current of the river is 5km, what was boat speed?
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 

Hi

distance the same Up and Back...

D = rt =  %28r-5%29%281%2F3%29+=+%28r%2B5%29%281%2F4%29  |Multiplying thru by 12 so as all denominators = 1

  4(r-5) =3(r+5)

 r = 35kmph

And..

 30/3 = 40/4