word problem: rowing up- and downstream; speed of current?

[Danielita]

Please help me on this it is my take home test and I don't understand !!!

Rhoda Skiff rowed her boat upstream 600 feet, then reutrned downstream to her starting point. Rhoda rowed at a speed of 8 ft./sec. through the water on the first part of the trip, but only 6 ft./sec. on the return trip. The round trip took 200 seconds. How fast was the current?

 

[galactus]

Distance equals rate times time, d=rt.

We know the time is 200 seconds

d/r=t

Let s=rate of current.

Distance is 600 feet upstream and 600 feet back downstream.

If she rows at 8 ft/sec upstream, she is rowing against the current.

Downstream, she is rowing 6 ft/sec. with the current.

\(\displaystyle \L\\\frac{600}{8-s}+\frac{600}{6+s}=200\)

Solve for s.