this is a lowest common multiple question.
to find the lowest common multiple, you need to find the prime factors of the two numbers:
[tex]8 = 2 , 2 , 2[/tex]
[tex]12 = 2 , 2 , 3[/tex]
Take out duplicates:
[tex]2,2,2,3[/tex]
and multiply them together:
[tex]2*2*2*3 = 24[/tex]
and that is your answer.
Easy peasy.