Xiao Ming reads 12 pages of the storybook every day for 5 days, and only 20% of the book is left. How many pages does this storybook have?
小明每天看12页故事书，看了5天，还剩下全书的20%，这本故事书共有多少页？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">5 / (4/5)</gadget>
<output>25/4 = around 6.25</output>

<gadget id="calculator">12 * (25/4)</gadget>
<output>75</output>

<result>75</result>