Xiao Ming reads a storybook. He reads 30 pages on the first day and 42 pages on the second day. He reads 20% more of the whole book on the second day than on the first day. After finishing the book in three days, this storybook How many pages are there?
小明看一本故事书，第一天看了30页，第二天看了42页，第二天比第一天多看了全书的20%，三天看完这本书，这本故事书一共有多少页？
<gadget id="calculator">42 - 30</gadget>
<output>12</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">12 / (1/5)</gadget>
<output>60</output>

<result>60</result>