Question

A motorboat takes

Answer 1

108=3(b-s)

36=b-s

s=b-36

...

108=2(b+s), and using s found above gives us:

54=b+b-36

54=2b-36

2b=90

b=45, and since s=b-36, s=9

So the boat's speed is 45mph and the stream's speed is 9mph