If a dozen people get on a train, and five of them get off at the next stop, how many of those people are left on the train? *

So we want to know how many people are left on the train if a dozen people entered the train and 5 of them got off on the next stop. So we need to know that a dozen is equal to 12. So now we can calculate: if 12 people first entered the train and 5 people left, 7 of them remained on the train.