Liu Ming finished reading a book in three days. He read 20% of the book on the first day, twice as much on the second day, and 60 pages on the third day. How many pages does this book have?
刘明三天看完一本书，第一天看了20%，第二天看的是第一天的2倍，第三天看60页，这本书有几页？
<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 - (1/5) - (2/5)</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">60 / (2/5)</gadget>
<output>150</output>

<result>150</result>