A storybook, A reads fewer pages than B every day (1/5), and B takes 8 days to finish reading the book, how many days does it take A to finish reading the storybook?
一本故事书，甲每天读的页数比乙少(1/5)，乙读完这本书用了8天，甲用多少天读完这本故事书．
<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">1 / 5</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">(1/8) * (4/5)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 / (1/10)</gadget>
<output>10</output>

<result>10</result>