How do you calculate theoretical probability?

Iknow its nothing to do with education, but what type of thing should i wrote here? ? : ) its for mcdonald's btw.

Which problem would you use the following proportion to solve for? 24/x = 40/100 a. what is 40% of 24? b. what percent is 24 of 40? c. twenty-four is 40% of what number? d. forty percent of 24 is what number?

Which problem would you use the following proportion to solve for? 24/x=40/100 a. what is 40% of 24? b. what percent is 24 of 40? c. twenty-four is 40% of what number? d. forty percent of 24 is what number?