Question: Jenny is working on a school project. She spends 10 hours doing research for the project and 2 hours writing a proposal. If she has 20 hours total to work on the project, how many hours does she have left to write her report? Think carefully first, then make a decision:
So far, Jenny has spent 10 + 2 = 12 hours on the project. Thus, she has 20 - 12 = 8 hours to write her report. So the answer is 8.