Hi, new here. I got a question here that I do not understand how to do at all. It'd be nice if someone explained how to solve it.

It took a crew 80 minutes to row 3km upstream and back again. If the rate of the flow of the stream was 3km/h, what was the rowing rate of the crew.

I did:

3=(1.33)(x+3)

3=(1.33)(x-3)

I was going to solve by substitution but I realized that 1.33 cannot be the time for both going up and downstream.