Question

A ferry can travel 100 miles with the current in the same amount of time it takes to travel 60 miles against the current. If the speed of the ferry is 40 mph, what is the speed of the current?

Answer 1

`(100)/(40+x) = (60)/(40-x)`
cross multiply
100(40-x) = 60(40 + x)
solve for x
x= 10