<PRE><B>Question 40797</B>
A boat can travel 9 miles upstream in the same amount of time it takes to tarvel 11 miles downstream. If the current of the river is 3miles per hour, complete the chart below and use it to find the speed of the boat in still water.
distance = rate * time
UPSTREAM 9 r-3
DOWNSTREAM 11 r+3

Time= distance/rate
EQUATION:
Time up = Time down
9/(r-3)=11/(r+3)
Cross-multiply to get:
9r+27=11r-33
2r=60
r=30 mph (speed of the boat in still water)
Cheers,
Stan H.</PRE>