A cylindrical glass tank has a bottom area of 50 square centimeters and a water depth of 12 cm. After a stone is completely submerged in water, the water level rises to 16 cm, what is the volume of the stone?
一个圆柱形玻璃缸，底面积是50平方厘米，缸内水深12厘米．把一块石头完全浸入水中后，水面升到16厘米，求石块的体积？
<gadget id="calculator">16 - 12</gadget>
<output>4</output>

<gadget id="calculator">50 * 4</gadget>
<output>200</output>

<result>200</result>