Each of the students in Mr. Mcdonald's class sold 16 raffle tickets. If each ticket costs $15, how much money did Mr. Mcdonald's students raise?

You do 16*15 and get 240

Well if each student sold 16 raffles, with each one that costs $15.

16*15=$240, but since you didn't give a specific number of students:

For the final step, take 240 and multiply it by how many students were in his class.