72 and 96. 72 is the answer once you multiply 18 by 4, 12 by 6, and 9 by 8. As for 96, you need to multiply 24 by 4, 16 by 6 and 12 by 8. If you divide 72 and 96 by 4, 6, and 8, you won't get any remainder for the answer - effectively making it a multiple of the three numbers.