The answer to your question is answer choice D
She can't spend more than 5 minutes on each of the remaining 8 questions.
It's a 60-minute test in which she has spent 20 minutes answering 12 questions. That means that there are 40 minutes remaining (60-20) to answer the remaining 8 questions. That's 40 divided by 8 = 5.
I believe the answer is 1/x-4
This is because the x-5 on the numerator and denominator cancel out
0.7/1 of a wall per person
