Sheet # 310
Name_________________________Date:_____________

1) Tom set his Christmas lights so that the green light goes on every 2 seconds and the red light every 3 seconds. When the light are turned on, how many seconds will it take for the green and red lights to go on at the same time?






2) Janet set her Christmas lights so that the green light goes on every 4 seconds and the red light every 6 seconds. When the lights are turned on, how many seconds will it take for the green and red lights to go on at the same time?






3) Mark set his Christmas lights so that the green light goes on every 3 seconds and the red light every 5 seconds. When the lights are turned on, how many seconds will it take for the green and red lights to go on at the same time?






4) Janet set her Christmas lights so that the green light goes on every 4 seconds and the red light every 5 seconds. When the lights are turned on, how many seconds will it take for the green and red lights to go on at the same time?













































Answers for sheet # 310

1) LCM of 2 and 3 is 6. 6 seconds later both lights will go on.

2) LCM of 4 and 6 is 12. 12 seconds later

3) LCM of 3 and 5 is 15. 15 seconds later

4) LCM of 4 and 5 = 20 . 20 seconds later