The "Open" sign at Cenzo's flashes every 4 seconds. The "Open" sign at The Kettle flashes every 5 seconds and the "Welcome" sign at Centrella's Deli flashes every 6 seconds. If the signs are turned on and flash at the same time, how long will it take for them to flash at the same time again?
It will take 60 ( one minute) for the signs to flash at the same time
Find the lcm ( least common denominator) 4: 4,8,12,16,20,24,28,32,36,40,44,48,52, 56,60 5: 5,10,15,20,25,30,35,40,45,50,55,60 6: 6,12,18,24,30,36,42,48,54,60