Xiao Ming reads an extra-curricular book. He reads 30% of the book on the first day and 24 pages on the second day. At this time, the ratio of the number of pages he has read to the number of pages he has not read is 2:3. How many pages does this book have?
小明看一本课外书，第一天看了全书的30%，第二天看了24页，这时已看页数与未看页数的比是2：3，这本书有多少页？
<gadget id="calculator">2 + 3</gadget>
<output>5</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

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

<gadget id="calculator">(2/5) - (3/10)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">24 / (1/10)</gadget>
<output>240</output>

<result>240</result>