Rational and inequalities equations

Question

A barge travels at an average of 7 miles per hour in still water. The barge travels 50 miles up the Mississippi River and 50 miles down the river in a total of 17.5 hours. What is the average speed of the current in miles per hour in this section of the Mississippi River?

Answer 1

current = 3mph, barge goes 7 mph in still water

7+3 = 10 mph down stream

7-3 = 4 mph up stream

50/10 = 5 hours down stream, 50/4 = 12.5 hours up stream a total 17.5 hours