Question

Joe must choose a number between 49 and 95 that is a multiple of 3 , 9, and 12 . Write all the numbers that he could choose. If there is more than one number, separate them with commas.

Answer 1

The only number that is a multiple of 3, 9, and 12 between 49 and 95 is 72

Answer 2

The first number 49 or larger that is divisible by 3 is 51 (17 * 3 = 51) so begin at 51 and count by 3's until you get to 95:51, 54, 57, 60, 63, 66, 69, 72, 75, 78, 81, 84, 87, 90, 93The first number 49 or larger that is divisible by 6 is 54 (6 * 9 - 54) so begin at 54 and count by 6's until you get to 95:54, 60, 66, 72, 78, 84, 90The first number 49 or larger that is divisible by 9 is 54 (9 * 6 - 54) so begin at 54 and count by 9's until you get to 95:54, 63, 72, 81, 90Now look for the numbers that are in all three lists