Mengmeng likes to insist on reading extracurricular books every day, so his knowledge horizon is very broad. Recently, he was reading a "Encyclopedia of Popular Science Knowledge". He read 30 pages on the first day, and 30% of the whole book on the second day. He just read the whole book (3/5) in two days. How many pages are there in this "Encyclopedia of Popular Science Knowledge"?
蒙蒙喜好坚持每天读课外书籍，因此他的知识视野很广．近来他在读一本《科普知识大全》，第一天读了30页，第二天又读了全书的30%，两天正好看了全书的(3/5)．这本《科普知识大全》共多少页？
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

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

<gadget id="calculator">30 / (3/10)</gadget>
<output>100</output>

<result>100</result>