A knapsack sprayer, the bottom area of the liquid medicine tank is 8 decimeters square, and the height of the liquid medicine is 2.5 decimeters. If 500 ml of liquid medicine is sprayed out every minute, how many minutes does it take to spray a box of liquid medicine?
一种背负式喷雾器，药液箱的底面积是8平方分米，药水高2.5分米．如果每分钟喷出药液500毫升，喷完一箱药液需要多少分钟？
<gadget id="calculator">1_000 / 500</gadget>
<output>2</output>

<gadget id="calculator">8 * 2.5 * 1 * 2</gadget>
<output>40</output>

<result>40</result>