Molly and her parents love to hang out at the beach on weekends. Molly spent the better part of the day at the beach and saw 100 people join them. At 5:00, 40 people left the beach. What's the total number of people at the beach if they all stayed until evening? Give me reasons, before answering the question
Molly and her parent were 2 + 1 = 3 people. When 100 more people joined, the total number became 3 + 100 = 103. If 40 people left before evening, the number reduced to 103 - 40 = 63 people. So the final answer is 63.