Answer: A.) 330 ways
Explanation:
We are to determine the number of subsets with 4 elements that can be formed from a set containing 11 elements.
Since the arrangement doesn't matter, it's a combination problem.
We are to take out a subset containing 4 elements at a time ; from a set with 11 elements
Recall :
nCr = n! / (n-r)! r!
11C4 = 11! / (11 - 4)! 4!
11C4 = 11! / 7!4!
11C4 = (11 * 10 * 9 * 8) / 4 * 3 * 2 * 1
11C4 = 7920 / 24
11C4 = 330 ways