Persevere with Problems

Question

Persevere with Problems A barge on the Mississippi River travels 40 miles upstream (against the current) in 5 hours. The return trip downstream (with the current) takes the barge only 4 hours. Use a system of equations to find the speed of the barge in still water and the speed of the current.

Answer 1

4(b+c)=80

b+c =20

5(b-c)= 80

b-c= 16

2b=20+16=36

b=18 mph = barge speed in still water

c = 2 mph = current speed