Will anyone help me set these two problems up? tHanks so muchhhh!!!
1. John can paint a house in 30 hours and Jerald can paint a house in 5 hours. How long would it take the two of them to paint a house together?
2. In mixing some fuel, a scientist combines a 50% ethanol sotluion with a 90% ethanol solution to get 40 liters 80% ethanol solution. How much of the 50% solution did the scientist use in the mixture?