Xiaoli borrowed a copy of "Robinson Crusoe" from the library. She read 15% of the whole book on the first day, and 25% of the whole book on the second day. There are 144 pages left. Page?
小丽在图书馆借了一本《鲁滨逊漂流记》，她第一天看了全书的15%，第二天看了全书的25%，还剩144页没看，这本书共有多少页？
<gadget id="calculator">15 / 100</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 - (3/20) - (1/4)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">144 / (3/5)</gadget>
<output>240</output>

<result>240</result>