An inequality can be formed by simply translating the problem statement to numerical expressions.
From the problem we know that

added with

hours should be equal or greater than

(helpful insight from the keyword "at least"). Therefore, it's inequality would look like:

(>= is used instead of ≥ for constraints in formatting)
The inequality above best models the situation.
Couldn’t quite read everything, the writing is very light. But from what I could read, it was correct for the most part. :)
Answer:
The surface area of the prism is 108 square in.