What was the total amount of revenue…
We are given that a theater sold 400 tickets, some at full price and others at x percent of the full price. Let’s let F = the price of the full price ticket. We will now express x percent as x/100 (in the same way that 85% is expressed as 85/100); thus, the price of the discounted ticket is (x/100)F. We need to determine the total amount of revenue made from the 400 tickets.
Statement One Alone:
x = 50
Using the information in statement one we know that the discounted ticket is (50/100)F, or 0.5F. However, without knowing the value of F or the number of discounted and full price tickets sold, we cannot determine the total revenue. Statement one alone is not sufficient to answer the question. We can eliminate answer choices A and D.
Statement Two Alone:
Full-price tickets sold for $20 each.
Since we do not have any information about the number of full-price tickets sold or the price of the discounted tickets, statement two is not sufficient to determine the total revenue. We can eliminate answer choice B.
Statements One and Two Together:
Using statements one and two we can determine that the discounted tickets were sold at 0.5(20) = 10 dollars, and we know that the full price ticket is 20 dollars. However, because we do not know the number of full price and discounted tickets that were sold, we cannot determine the total revenue.