Xiaohong reads a book. She reads 10% of the whole book in the first week, and 1/4 of the whole book in the second week. There are 130 pages left. How many pages does this book have?
小红看一本书，第一周看了全书的10%，第二周看了全书的(1/4)，还剩130页没看，这本书共有多少页？
<gadget id="calculator">10 / 100</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 - (1/10) - (1/4)</gadget>
<output>13/20 = around 0.65</output>

<gadget id="calculator">130 / (13/20)</gadget>
<output>200</output>

<result>200</result>