A wine bottle contains 500 ml of solution. Measure the height of the solution to be 25 cm. Turn the bottle upside down. The height of the empty part above the page is 5 cm. Find the volume of the bottle.
一个酒瓶内装溶液500毫升，量得溶液高度为25厘米，将瓶倒置，页面上空部分高度为5厘米，求瓶子的容积．
<gadget id="calculator">500 / 25</gadget>
<output>20</output>

<gadget id="calculator">25 + 5</gadget>
<output>30</output>

<gadget id="calculator">20 * 30</gadget>
<output>600</output>

<result>600</result>