1. The problem statement, all variables and given/known data Marlene rides her bicycle to her friend Jon's house and returns home by the same route. Marlene rides her bike at constant speeds of 6 mph on level ground, 4 mph when going uphill, and 12 mph when going downhill. If her total time riding was 1 hour, how far is it to Jon’s house? Answer = 3 miles 2. Relevant equations d=rt t=d/r 3. The attempt at a solution t1+t2+t3=1hour L/6mph+U/4mph+D/12mph=1hour I have tried solving for each variable independently and then substituting it, but when I do that all my terms cancel out and I am either left with 1=1 or 12=12 depending of which equation I start with. I understand that Marlene traveled different distances at different rates, and for different intervals of time. I know that the total distance traveled in 1 hour must be 6 miles but I can't seem to express it mathematically.