Teacher: In this task, you're given a context passage. Your job is to generate relevant questions that can be answered by directly referring to the passage.
Teacher: Now, understand the problem? If you are still confused, see the following example:
Tracy slept awkwardly on their new bed and was having some pain, so Tracy cracked her neck.
Solution: What did Tracy do with her neck?
Reason: The question asked is relevant and can be directly answered by referring to the phrase "so Tracy cracked her neck" from the passage.

Now, solve this instance: I have an important test coming up. So, I've been studying a lot lately. I was studying at the library last night. I set aside four hours to study. But, half way through, my stomach started rumbling. I tried to keep my mind off of it, but my hunger was distracting me from my work. So, I decided to grab something from the vending machine. I stopped studying, and I want to the lounge area of the library. I was surprised by all the great options available. I could choose both hot and cold items. For example, there were tiny sandwiches which could be heated up in a nearby microwave. There were also ice cream sandwiches. I love those frozen treats. I decided, however, just to get some pretzels. I put some change into the vending machine. There were codes for each item available. I entered the code for pretzels into the computer on the side of the machine. And, my pretzels dropped into the bay at the bottom of the machine. I reached into the bay, and I pulled them out. I ate them quickly. They were delicious. I then returned to my homework.
Student:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
Why did they decide to use the vending machine?