Will read 20 pages of his mystery book every day. After reading for 5 days, Will still had 55 pages left. How many pages are in Will's mystery book?
Will has read 20 * 5 = 100 pages
that is, Will had read 100 pages
But it is given that, after reading for 5 days, Will still had 55 pages left
therefore 20 * 5
= 100
= 100 + 55 = 155
Total number of pages in the book = 155
