1. The problem statement, all variables and given/known data A boat takes 2.0 hr to travel 31 km down a river, then 6.0 hr to return. How fast is the river flowing? 2. Relevant equations r=d/t 3. The attempt at a solution first started out by finding the rate the boat traveled in each trip. 31/2=15.5 km/hr 31/6=5.2 km/hr Now this is where im not sure if im solving this correctly. I then find the difference between the two rates and the time taken to travel both ways. 10.3 (difference of 15.5-5.2)/4(difference of 6-2)=2.6 km/hr Is this the correct way of solving this problem? Thanks!