Okay. So if you solve for the difference, the common difference is 7. Monday is first in the pattern and there are 7 days in one week. Sunday makes the 7th day. The formula for finding patterns is an = a1 + (n - 1)d, where n is the number term we are looking for and d is the difference. 7 is the term we are looking for. 7 - 1 is 6. 6 * 7 is 42. Now, we can add 25, which is the first term in the sequence. 42 + 25 is 67. There. Mr. Moore will read 67 pages on Sunday.