There are 50 bottles of Sprite. After selling 20% of them, they put 20% of the remaining Sprite in the box. How many bottles of Sprite are there in the box? How many.
有50瓶雪碧，卖出它的20%以后，又装入箱子里所剩雪碧的20%，这时箱子里有雪碧多少瓶．多少．
<gadget id="calculator">20 / 100</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 + (1/5)</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">50 * (4/5) * (6/5)</gadget>
<output>48</output>

<result>48</result>