Question

A woman rows a boat 1.75 miles upstream against a constant current in 35 minutes. She then
rows the same distance downstream (with the same current) in 15 minutes. What is the rate of
the current?

Answer 1

since distance = speed * time,
if the current is c and her speed is s,

35(s-c) = 1.75
15(s+c) = 1.75

Now just solve for c.