Question

A boat makes a 120-mile trip downstream in 3 hours but makes the return trip in 4 hours. If b = the rate of the boat in still water and c = the rate of the current, which of the following equations represents the trip downstream?
a.)3(b - c) = 120
b.)3(b + c) = 120
c.)4(b + c) = 120

A boat makes a 120-mile trip downstream in 3 hours but makes the return trip in 4 hours. What is the rate of the boat in still water?


a.)30 mph
b.)32 mph
c.)35 mph

Please tell me how to do these. Im horrible at understanding word problems more than normal problems.