need help before test!!!

Question

a boater travels upstream at top speed to his favorite fishing spot, a distance of 224 miles, in 4 hour. Returning, he finds that the trip downstream, still at top speed, takes only 3.5 hr. Find the rate of the boat and the speed of the current.

 

Boats rate mph......

current rate mph.......

Answer 1

Let b=boat's rate and c=current's rate.  Using distance = rate x time, we have

 

               4(b-c) = 224

             3.5(b+c)=224

 

Dividing top equation by 4 and bottom equation by 3.5, we obtain

 

                  b-c=56

                  b+c =64

 

Adding the two equations, we get 2b=120.  So b=60 mph and c=4 mph.