Xiao Ming reads a storybook and has read 75% of the whole book, leaving 30 pages unread. How many pages does this storybook have?
小明读一本故事书，已经读了全书的75%，还剩30页没有读，这本故事书共有多少页？
<gadget id="calculator">75 / 100</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">1 - (3/4)</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">30 / (1/4)</gadget>
<output>120</output>

<result>120</result>