8 and 12 are each factors of all of these, and they go on forever. 24, 48, 72, 96, 120, 144, 168, 192, 216, 240, 264, 288, ... So K could be any of these. However I think you might have wanted K to be the LEAST common multiple of 8 and 12, which is the SMALLEST ONE in the above list, which is 24. Edwin