Xiao Ming reads a story book. He reads 20% of the total pages in two days, and starts from page 41 on the third day. How many pages does the book have?
小明读一本故事书，两天读了总页数的20%，第三天从41页开始读起，这本书共多少页．
<gadget id="calculator">41 - 1</gadget>
<output>40</output>

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

<gadget id="calculator">40 / (1/5)</gadget>
<output>200</output>

<result>200</result>