A family is moving and has a number of electronic devices in the same packing crate. One of the devices beeps every 8 minutes, another device beeps every 10 minutes, and a third device beeps every 12 minutes. If all the devices beeped together at 3:00 pm, what time will it be when they all beep together next?
First, you need to find the Least Common Multiple of all of 8, 10, and 12. It is 120. To convert the 120 minutes to hours, divide by 60, which yeilds 2. So, the next time all the devices beep together will be 2 hours later, or 5:00 PM.