Distance math word problem

Question

A boat goes 240 miles down stream in the same time it can go 160 miles upstream. The speed of the current is 5 miles per hour. What is the speed of the boat in still water?

Answer 1

Hello Leah,

 

Distance    Rate        Time

    240       r + 5          t      for the boat going downstream

    160       r-5             t      for the boat going upstream

 

r = speed of the boat in still water

t = time traveled

 

If d = rt, the t = d/r

 

240/(r+5) = 160/(r-5)

240r-1200 = 160r+800

 

Solving for r

80r = 2000

r = 25 mph <---speed in still water