You have reading homework every 6 days and science homework every 15 days. If you have homework in both today when will you have homework in both subjects again on the same day?
Do you remember when you were learning about the "Least Common Multiple" of two numbers, and you were wondering why you had to learn it, because you were so sure that you'd never need to use it ? Do you remember that ?
Well, HERE's where you get to use it. This question is just looking for the LCM of 6 and 15 . THAT's how many days it will be before you get homework in both subjects on the same day again.
