A boat takes a long trip traveling 140 miles downstream in 7 hours. The return trip upstream takes 10 hours. Let b be the rate of the boat in still water in miles per hour and let c be the rate of the current in miles per hour.

In order to determine the two equations of the system described here use the formula that distance = rate times time.

Question

A boat takes a long trip traveling 140 miles downstream in 7 hours. The return trip upstream takes 10 hours. Let b be the rate of the boat in still water in miles per hour and let c be the rate of the current in miles per hour. 
 
 In order to determine the two equations of the system described here use the formula that distance = rate times time.

Quizplus · Accepted Answer

Using the formula distance = rate times time, we can set up the following equations for the downstream and upstream trips:

Downstream: 140 = (b + c) * 7
Upstream: 140 = (b - c) * 10

These two equations can be used to solve for both the rate of the boat in still water (b) and the rate of the current (c).

A Boat Takes a Long Trip Traveling 140 Miles Downstream