1. A boy must take a red tablet every 20 minutes and a blue tablet every 35 minutes. If he takes both tablets at 12pm, what time will he next take both tablets together?
This question can be answered by finding the lowest common multiple of 20 and 35, which is 140 minutes and adding this onto 12pm, or by starting at 12pm and going up in 20 minutes and 35 minutes until a matching time of 2:20pm is found.
