Li Nan finished a book in three days, read the whole book (3/10) on the first day, read 24 pages on the second day, and left the whole book (2/5) unread. How many pages does this book have?
李楠三天看完一本书，第一天看了全书的(3/10)，第二天看了24页，还剩下全书的(2/5)未看．这本书共有多少页？
<gadget id="calculator">3 / 10</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (3/10) - (2/5)</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">24 / (3/10)</gadget>
<output>80</output>

<result>80</result>