Question

Tom and Amy set the alarms on their phones to sound at 6:45am. Both alarms sound together at 6:45am. Toms alarm then sounds every 9 minutes. Amy's alarm then sounds evrey 12 minutes. At what time will both alarms next sound together?

Answer 1

36 minutes. ie 7:21 am
here is how yuo do it. find the least common factor, which is 3. from here you divide both by 3, you get 3 and 4, multiply the 12 by 3 and the 9 by 4 and boom 36 minutes lader :DDD

Answer 2

36 is a multiple of both 12 and 9, so it could be 36 minutes later?

So it should be 7:21am