To read a science and technology book, it takes 36 days for the elder brother to finish reading, and 40 days for the younger brother to finish reading. It is known that the elder brother reads 2 pages more than the younger brother every day. How many pages does this book have?
读一本科技书，兄读完要36天，弟读完要40天，已知兄每天比弟多读2页，这本书有多少页？
<gadget id="calculator">1 / 36</gadget>
<output>1/36 = around 0.027778</output>

<gadget id="calculator">1 / 40</gadget>
<output>1/40 = around 0.025</output>

<gadget id="calculator">(1/36) - (1/40)</gadget>
<output>1/360 = around 0.002778</output>

<gadget id="calculator">2 / (1/360)</gadget>
<output>720</output>

<result>720</result>