The current of a river is 3 miles per hour. A boat travels to a point 8 miles upstream and back in 5 hours, find the speed of the boat in still water

Question

math help

 

Answer 1

If I am understanding your question, the total upstream is 8 miles and another 8 miles downstream.

Let s = the speed of the boat in still water

d = rt

8 = 5(s + 3)  downstream

8 = 5s + 15  equation 1

8 = 5(s - 3)   upstream

8 = 5s - 15    Add equation 1

8 = 5s + 15 

16 = 10s    Divide both sides by 10.

s = 16/10 = 8/5 = 1.6 mph