Problema Solution

A boat travels 9 kilometers upstream in the same amount of time it moves 16 kilometers downstream. If the rate of the current is 6 kilometers per hour, find the rate of the boat in still water.

Answer provided by our tutors

distance=rate*time.

9=(r-6)t upstream

16=(r+6)t downstream.

seeing as the times are equal we have:

9/(r-6)=16/(r+6)

16r-96=9r+54

 

16r-9r=54+96

7r=150

r=21.43 kl/h speed of the boat in still water.

proof

9/(21.43-6)=16/(21.43+6)

9/15.43=16/27.43

.5833=.5833