Question: At a bus station, a bus leaves every half-hour for 12 hours a day. How many buses leave the station for 5 days? Think carefully first, then make a decision:
If one bus leaves every half - hour, then during one hour, there are 1 + 1 = 2 buses that leave the station. During 5 days 2 * 12 * 5 = 120 buses leave the station. So the answer is 120.