Joey has 30 pages to read for history class tonight. He decided that he would take a break when he finished reading 70% of the pages assigned. How many pages must he read after he takes a break? Let's be accurate as possible.
Joey will take a break after 30 * 0.7 = 21 pages. Joey will have to read 30 - 21 = 9 pages more.
The answer: 9.