Question

Two light house their lights every 30 seconds and 48 seconds.they flashed together at 8:00 pm.when will they next flash together

Answer 1

Answer:

$lcm \: of \: 48 \: and \: 30 \: second \\ = 4 \: minut \\ so \: the \: light \: house \: next \: flash \: on \: 8.4pm$