Question 129450
let x=current __ time equals distance divided by rate


"It travels 75 miles downstream with the current" __ 75/(10+x)


"in the same time" __ =


"it travels 25 miles upstream" __ 25/(10-x)


{{{75/(10+x)=25/(10-x)}}}


dividing by 25 and "cross" multiplying __ 3(10-x)=1(10+x) __ 30-3x=10+x __ 20=4x