For a book, if you read 30% of the whole book on the first day, and read 50% of the pages on the second day, how much of the whole book did you read on the second day?
一本书，第一天读了全书的30%，第二天读的页数是第一天的50%，第二天读了全书的多少？
<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">50 / 100</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(3/10) * (1/2)</gadget>
<output>3/20 = around 0.15</output>

<result>3/20 = around 0.15</result>