On Wednesday, 1/3 of the students in Mr. Short's homeroom had drama practice, and 3/4 of his other homeroom students had band practice. If 8 students had band practice, how many students are in Mr. Short's homeroom?

I think there is a mistake in your question! I think 8 should be 9. If that is so, then:

Let the total number of students ==S

S - 1/3S ==2/3S

3/4 * 2/3S ==9

1/2S ==9

S ==9 * 2 ==18 - total number of students in Mr. Short's class.