A boat in still water is 32 mph. If the boat travels 72 miles upstream in the same time that it takes to travel 120 miles downstream, find the speed of the current.

Dup = 72 miles

ddown = 120 miles

v = riverspeed

rup = 32mph - v

rdown = 32mph + v

t both ways = t

d=r*t

d/r=t

t=ddown/rdown

t=dup/rup

dup/rup = ddown/rdown

(72) / (32-v) = (120) / (32+v)

3840-120v=2304+72v

1536=192v

v=8