Question 156525
d=r*t
d=(16-c)*20
d=(16+c)*15
(16-c)*20=(16+c)*15
320-20c=240+15c
-20c-15c=240-320
-35c=-80
c=-80/-35
c=2.285 mph is the speed of the current.
Proof:
(16-2.285)*20=(16+2.285)*15
13.715*20=18.285*15
274.3=274.3