On an assignment students are expected to answer at least 3

On an assignment, students are expected to answer at least 3 questions from a 25 question set. But they can complete as many questions as they wish (for bonus!). How many possible ways can they complete the assignment? Note: Consider all questions do-able, and each student will complete at least the minimum number of questions.

25 - 3 = 22

22 different ways to complete the assigment