I read (1/4) of a book on the first day, and (1/7) on the second day. I read a total of 33 pages in two days. How many pages does this book have?
一本书第一天看了它的(1/4)，第二天看了它的(1/7)，两天共看了33页，这本书共多少页？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 / 7</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">(1/4) + (1/7)</gadget>
<output>11/28 = around 0.392857</output>

<gadget id="calculator">33 / (11/28)</gadget>
<output>84</output>

<result>84</result>