Question

A high school student needs 9 more classes to graduate. If she has met the prerequisites for all the classes, how many possible schedules for next semester could she make if she has 5 class periods to fill? (enter the answer with no commas, i.e. as 1000 not 1,000.) I answered with 126 and got this wrong. I almost had a perfect score! Can someone show me what I did wrong? This does not seem like a hard question. Is the format jacked up again? I am tired of getting problems wrong when I know I used the correct formula.

Answer 1

Answer: 126

Explanation:

The problem asks how many possible schedules a high school student can make for next semester if she has 5 class periods to fill and needs to take 9 more classes to graduate, assuming she has met the prerequisites for all the classes.

To solve this problem, we can use the combination formula, which gives us the number of ways to choose k items from a set of n items. In this case, we want to choose 5 classes from the 9 remaining classes. Therefore, the number of possible schedules is given by:

C(9,5) = 9! / (5! * (9-5)!) C(9,5) = 126

So the answer is 126.