Question: There was only enough room for 21 people on a raft if no one wore life jackets. There were 7 fewer people who could fit on the raft if everyone wore life jackets. If 8 people on the raft needed life jackets, how many people could fit on the raft? Think carefully first, then make a decision:
If everyone wore life jackets, only 21 - 7 = 14 people could fit on the raft. For every person less on the raft, 14 / 7 = 2 life jackets could fit. For 8 life jackets, 8 / 2 = 4 less people could fit. 21 - 4 = 17 people could fit on the raft. So the answer is 17.