You need to form 2 equations for x and y, or whatever variable you use.

Question

A boat on a river travels down stream between two points, 20 miles apart, in 1 hour. The return trip against the current takes 2 1/2 hours.  What is the boat speed and how fast does current flow in the river ?

Answer 1

Let R be the speed of boat

 

Let C be rate of current

 

R times T = Distance

 

X + C is speed downstream

 

X - C is speed upstream

 

(X + C) 1 = 20

 

(X - C) (2 1/2) = 20

 

Can you solve it from there?

If you need help let me know.