Question 1057070

A paddle boat can move at a speed of 6km/h in still water. The boat is paddled 16 km downstream in a river in the same time it takes to go 8 km upstream. What is the speed of the river?
<pre>Let speed of river be S
Time it takes to travel DOWNSTREAM: {{{16/(6 + S)}}} 
Time it takes to travel UPSTREAM: {{{8/(6 - S)}}}
We then get the following TIME equation: {{{16/(6 + S) = 8/(6 - S)}}}
8(6 + S) = 16(6 - S) ----- Cross-multiplying
6 + S = 2(6 - S) --------- Dividing each side by GCF, 8
6 + S = 12 - 2S
S + 2S = 12 - 6
3S = 6
S, or speed of river = {{{highlight_green(matrix(1,4, 6/3, or, 2, mph))}}}
It's that easy....nothing complex!!