SOLUTION: You and a friend decide to row down river, have a picnic and then row back home. The picnic spot is 20 miles from home. It takes you 2 hours to row with the current to the picnic s

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: You and a friend decide to row down river, have a picnic and then row back home. The picnic spot is 20 miles from home. It takes you 2 hours to row with the current to the picnic s      Log On


   

Question 1084998: You and a friend decide to row down river, have a picnic and then row back home. The picnic spot is 20 miles from home. It takes you 2 hours to row with the current to the picnic spot and 3 hours and 20 minutes to row back after the picnic. Determine the rate of the current and the rate at which you rowed.
Found 2 solutions by jorel1380, MathTherapy:
Answer by jorel1380(3719) About Me  (Show Source):
You can put this solution on YOUR website!
Let r be your rowing speed and c be the speed of the river. Then
20/(r+c)=2
20/(r-c)=10/3
So:
2r+2c=20
10r-10c=60
Solve for r and c. ☺☺☺☺

Answer by MathTherapy(10551) About Me  (Show Source):
You can put this solution on YOUR website!

You and a friend decide to row down river, have a picnic and then row back home. The picnic spot is 20 miles from home. It takes you 2 hours to row with the current to the picnic spot and 3 hours and 20 minutes to row back after the picnic. Determine the rate of the current and the rate at which you rowed.
Let rowing speed be S, and current speed, C

Then rowing with the current gives: 

Rowing against the current gives: 

2S = 16 ------ Adding eqs (ii) & (i) 

S, or rowing-speed = highlight_green%28matrix%281%2C4%2C+16%2F2%2C+or%2C+8%2C+mph%29%29

Now, you find the speed of the current!