The bottom area of a cylindrical glass container is 4 square decimeters, pour 6.5 liters of water into the container, and then put a conical iron piece with a height of 15 cm into the water. At this time, the depth of water in the container was measured to be 20 cm. What is the area of the base of this conical piece of iron?
一个圆柱形玻璃容器的底面积是4平方分米，向容器中倒入6.5升水，再把一个高为15厘米的圆锥形铁件放入水中．这时量得容器内的水深20厘米．这个圆锥形铁件的底面积是多少平方分米？
<gadget id="calculator">20 / 10</gadget>
<output>2</output>

<gadget id="calculator">4 * 2</gadget>
<output>8</output>

<gadget id="calculator">8 - 6.5</gadget>
<output>1.5</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1.5 / (1/3) / 1.5</gadget>
<output>3</output>

<result>3</result>