A cylindrical plastic cup, pour 200ml of water, the height of the water is only 40% of the height of the cup. It is known that the bottom area of this cylindrical cup is 50 square centimeters, how high is this cup?
一个圆柱形塑料杯，倒进200毫升水，水的高度只有杯子高度的40%．已知这个圆柱形杯子的底面积是50平方厘米，求这个杯子有多高？
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">200 / 50 / (2/5)</gadget>
<output>10</output>

<result>10</result>