SOLUTION: A motor boat takes 5 hours to travel 200km going upstream. The return trip takes 4 hours going downstream. What is the rate if the boat in still water and what is the rate of the o

Algebra ->  Equations -> SOLUTION: A motor boat takes 5 hours to travel 200km going upstream. The return trip takes 4 hours going downstream. What is the rate if the boat in still water and what is the rate of the o      Log On


   

Question 1077233: A motor boat takes 5 hours to travel 200km going upstream. The return trip takes 4 hours going downstream. What is the rate if the boat in still water and what is the rate of the of the current?
Found 2 solutions by Boreal, josgarithmetic:
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
Goes upstream at 40 km/h, 200/5, which is speed of boat-current= s-c
Goes downstream at 50 km/h, s+c
s-c=40
s+c=50
2s=90
s=45 km/h speed in still water
c=5 km/h current

Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
                 SPEED     TIME     DISTANCE
UPSTREAM          r-c       5        200
DOWNSTREM         r+c       4        200

system%285%28r-c%29=200%2C4%28r%2Bc%29=200%29

system%28r-c=40%2Cr%2Bc=50%29------solve this system for r and c.

highlight%28system%28r=45%2Cc=5%29%29