Li Xue read a story book, the ratio of the number of pages read in the first book to the number of remaining pages is 3:7, and she read 18 pages in the next day, at this time the number of pages read in two days just accounts for the total number of pages in the book of (1/2). How many pages does this storybook have?
李雪同学读一本故事书，第一本读的页数与余下页数的比是3：7，第二天又读了18页，这时两天共读的页数正好占全书页数的(1/2)．这本故事书共有多少页？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">10 / (1/5)</gadget>
<output>50</output>

<result>50</result>