A red string of holidays lights blink once every 3 seconds while a string of lights blink every 4 seconds how many times will both sets of lights blink at the same time in 1 min

5 times. The lowest common multiple of 3 and 4 is 12, which means both lights will blink at the same time every 12 seconds. Since 60seconds divided by 12secs is 5, both lights like blink together a total of 5 times in a minute.