An essay test has 12 questions. Students are required to answer 8 of the 12 questions. How many different sets of questions could be answered?
There are different sets of questions that could be answered.

Step 1 ：This problem is about combinations. We are choosing 8 questions out of 12, and the order in which we choose the questions does not matter. The formula for combinations is: \[C(n, k) = \frac{n!}{k!(n-k)!}\] where n is the total number of items, k is the number of items to choose, and '!' denotes factorial, which is the product of all positive integers up to that number.

Step 2 ：In this case, n = 12 and k = 8.

Step 3 ：Substituting the values into the formula, we get \[C(12, 8) = \frac{12!}{8!(12-8)!}\]

Step 4 ：Solving the above expression, we find that the number of combinations is 495.

Step 5 ：Final Answer: There are \(\boxed{495}\) different sets of questions that could be answered.