For a storybook, Li Hong read 25% of the whole book on the first day and 30 pages on the second day. At this time, the ratio of the number of read pages to the number of unread pages is 2:3. How many pages does this storybook have? ?
一本故事书，李红第一天看了全书的25%，第二天看了30页，这时已看页数与未看页数的比是2：3，这本故事书有多少页？
<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">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(2/5) - (1/4)</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">30 / (3/20)</gadget>
<output>200</output>

<result>200</result>