Determining common multiples

Lessons

1. Give the first three multiples of the number.
   1. 9
   2. 21
   3. 45
2. A long term care facility serves lamb every sixth day and pork every eighth day. If lamb and pork are both on today's menu, how many days will it be before they are both on the menu again?
3. George's watch beeps every 20 minutes and Elizabeth's watch beeps every 25 minutes. Both watches just beeped. In how many minutes will both watches beep again?