A bus comes by Jerry's bus stop every 20 minutes starting at exactly 5:13 a.m. If Jerry shows up at exactly 8:35 a.m., how many minutes will he have to wait for the next bus?
8 - 5 = 3, so there are 3 hours difference. 35 - 13 = 22, so there are 22 minutes difference. To find the time of the next bus, I can add 20 minutes to 8:33 a.m. 8:33 + 0:20 = 8:53, so the next bus will come at 8:53 a.m. To find how long Jerry has to wait, I can subtract 8:35 from 8:53. 8:53 - 8:35 = 0:18, so Jerry has to wait 18 minutes for the next bus.

