Question

Clea attends music lessons every 2 weeks, dance class every 3 weeks, and has a dental appointment every 6 weeks. If she attends all three this week, when will she attend all three again

Answer 1

To find the next week in which all three coincide, look for the lowest common multiple of the numbers 2,3, and 6. Two has multiples of (2,4,6,8,10,12), three has (3,6,9,12,15,18), and 6 has (6,12,18,24). The lowest number that is common to all three values is 6, so Clea will attend all three in the same week 6 weeks from now.