There were 240 pages in a book. A student reads 10 pages on the first day, 14 on the second day and 16 pages on the third day. What fraction of the book was read and what fraction was left.

16% read is the answer

They read 10 + 14 + 16 = 40 out of 240 pages by the third day, putting them 40/240 = 1/6 of the way through the whole thing. If they've read 1/6 of the book, they have 5/6 left until they finish the whole thing.