Suppose a boat has to make a round trip up and down a river. The trip up takes 1 hour and is with the current. The trip back takes 6 hours. Suppose the round trip is a total of 34 miles, and that the boat's speed and the speed of the current are constant. What is the boat's speed and what is the current's speed?

1 answer

34/2 = 17

Upstream: 17 = b + c
Downstream: 17 = 6(b - c)

Rearrange the first equation....
c = 17 - b
Substitute that into equation 2.
17 = 6(b - (17 - b))

Solve for b, after you do that, then you plug in the value for b and solve for c using this.
c = 17 - b

b = boat speed
c = current speed.