Xiaoyun reads a story book, reads 25% of the whole book in the morning, exactly 50 pages, and reads the whole book again in the afternoon (2/5). How many pages did Xiaoyun read in the afternoon?
小云看一本故事书，上午看了全书的25%，正好是50页，下午又看了全书的(2/5)．小云下午看了多少页？
<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">50 / (1/4)</gadget>
<output>200</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">200 * (2/5)</gadget>
<output>80</output>

<result>80</result>