Answer
False
Work Step by Step
The multiples of 12 are 12, 24, 36,...
The multiples of 18 are 18, 36, 54,...
6 is the greatest common factor of 12 and 18 (the largest number that both 12 and 18 can be divided by) but it is not a multiple of either number.
Looking at the multiples listed above, you can see that 36 is the first (and smallest) number that is a multiple of both numbers. 36, then, is the least common multiple of 12 and 18.