Question 414223
speed of boat = xmph
current speed = 3 mph
..
upstream speed = x-3 mph
downstream speed = x+3 mph
...
distance = 30 miles
(3/5) *30/(x-3) = 30/(x+3)
18/(x-3)=30/(x+3)
18(x+3)=30(x-3)
18x+54=30x-90
30x-18x=90+54
12x=144
/12
x= 12 mph