Since you posted quotes from the books:

[Provide Class C’s finalized questions and answers for the end of term exam.] [Otherwise, make significant changes to the questions and answers you provide Kushida Kikyō.] This was the message that Ryūen had received. Usually, Ryūen wouldn’t respond to something like this. However, X had given him useful information that benefited Class C with no strings attached. The information was that Horikita Suzune had seen through Ryūen and Kushida’s tactics, and had made a preemptive strike. This had come out of the blue for Ryūen, who had been anticipating complete success with Kushida’s replacement of the exam questions. If not for this information, some of his classmates who were behind in their studies might have had to drop-out. Knowing this, Ryūen had three options available to him as to how to proceed.

Take a look at the part I have made bold. Does it look like it's possible to do that in 1 day. All the quotes you gave me from 1 day before the test. You really think it is possible to pass the extremely difficult test after 1 day of study. It is possible to make significant changes and get them approved just one day before the test