A certain medicine is 250ml per bottle, if the intravenous infusion rate is 5ml per minute, how many minutes will it take to finish instilling 2 bottles of such medicine.
某种药水每瓶250毫升，如果静脉滴注的速度是每分钟5毫升，那么滴注完这样的2瓶药水需要多少分钟．
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">250 * (2/5)</gadget>
<output>100</output>

<result>100</result>