Question

Sam and Martha are the local names for two lighthouses that guard a particularly dangerous part of the coast. Sam blinks every 12 seconds, and Martha blinks every 8 seconds they blink together at midnight. How many seconds will pass before they blink together again?

Answer 1

Write the repetitive numbers in order as many times as it takes until both are the same number. (what I mean is order the number in order by increasing (ex: 25, 50, 75, etc.))
Sam's blinks: 15, 30, 45, 60, 75, 90, 105
Martha's blinks: 25, 50, 75, 100, 125, 150, 175
They both have 75, so that is the amount of seconds. (answer: 75 seconds)