Question 251382
For the first choice, the student can pick any one of 20 choices. Now there are 19 questions left to choose from.
For the second choice, the student can pick any one of the remaining 19 questions. Now there are 18 questions left
Keep doing that same process until you have picked 7 questions.

{{{20*19*18*17*16*15*14}}} now just multiply and get your answer