Question

A motorboat takes

3
hours to travel
108mi
going upstream. The return trip takes
2
hours going downstream. What is the rate of the boat in still water and what is the rate of the current?

Answer 1

108 miles 3 hours = 36 mph upstream
108 miles 2 hours = 54 mph downstream

bv = boat velocity in still water
cv = current velocity

bv -cv = 36
bv +cv = 54 Adding both equations

2*bv = 90

boat velocity in still water = 45 mph

since bv + cv = 54
then we know the current velocity = 9 mph