Xiaohong reads a story book, and reads 60% of it in 3 days. According to this calculation, how many days will it take to finish it.
小红看一本故事书，3天看了60%，照这样计算，还要多少天才能看完．
<gadget id="calculator">60 / 100</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 - (3/5)</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(3/5) / 3</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(2/5) / (1/5)</gadget>
<output>2</output>

<result>2</result>