boat downstream

Question

If a boat in a 4mph current can travel 76 miles downstream in the same time it takes to travel 20 miles upstream, what is the speed of the boat in still water?

Answer 1

The current aids the boat going downstream and hampers it going upstream. d = rt, so t = d/r, and the times are equal.

 

76/(b + 4) = 20/(b - 4)

 

Cross multiply and solve for b. You got this!