500
Should you use GCF or LCM, find the correct one: The library at a high school runs videotapes of two study skill programs continuously. One videotape runs for 42 minutes and the second one runs for 56 minutes. Both videotapes begin at 9:00AM. When will the videos of the two programs begin again at the same time?
What is LCM = 168 minutes later or 11:48AM.