Wang Yang read a storybook. On the first day, he read 20% of the total pages. On the second day, he read 15 pages less than the first day. In two days, he read exactly (1/3) of the total pages. How many pages are there in this storybook?
汪洋读一本故事书，第一天读了总页数的20%，第二天比第一天少读了15页，两天正好读了总页数的(1/3)．这本故事书一共多少页？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/5) * 2</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(2/5) - (1/3)</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">15 / (1/15)</gadget>
<output>225</output>

<result>225</result>