Can someone explain to me what is n? i was very confused about this problem and my teacher didn’t review it in class! (don’t mind the answer choice that appears on the document)

An advertising firm has an old computer that can prepare a whole mailing in 6 hours. with the of newer model the job is complete in 2 hours. how long would it take the newer model to do the job alone?

What is the total surface area of this square pyramid?

The probability that a student graduating from suburban state university has student loans to pay off after graduation is .60. if two students are randomly selected from this university, what is the probability that neither of them has student loans to pay off after graduation?