Answer:
Total number of pages is 540.
Step-by-step explanation:
Let mark read x be he number of pages per day and d be the number of days to finish the book.
Total number of pages = xd
Mark reads 18 pages less per day than originally planned, he will need 5 extra days to finish the book.
.... (1)
He reads 24 pages less per day, he will need 8 extra days to finish.
... (2)
Subtract 5 times of equation (2) from equation (1).
Substitute d=10 in equation (1).
Divide both sides by 5.
Total number of pages
Therefore , the total number of pages is 540.