Question

Jade and Ali set the alarms on their phones to sound at 7.15 am.

Both alarms sound together at 7.15am.
Jade's alarm then sounds every 40 minutes.
Ali's alarm then sounds every 60 minutes.
At what time will both alarms next sound together?

Answer 1

Trust me its 9:15 am

Explanation:

Answer 2

9:15 am

Explanation:

Alarms sound at 7:15 am

Alarm frequencies are 40 min and 60 min

Since 40= 20*2 and 60= 20*3, the overlapping frequency is:

• 20*2*3= 120 min = 2 hours

So next time both alarms sound at 7:15 am + 2 hours = 9:15 am