cylindrical bucket, the diameter and height of the bottom surface are 40 cm, 85% of the volume of the bucket is filled with water, and each liter of water weighs 1 kg, how many kilograms of water is in the bucket?
一个圆柱形水桶，底面直径和高都是40厘米，用这个水桶容积的85%装水，每升水重1千克，桶中的水大约有多少千克？
<gadget id="calculator">40 / 2</gadget>
<output>20</output>

<gadget id="calculator">20 ** 2</gadget>
<output>400</output>

<gadget id="calculator">40 / 1_000</gadget>
<output>1/25 = around 0.04</output>

<gadget id="calculator">3.14 * 400 * (1/25) * 1</gadget>
<output>50.24</output>

<result>50.24</result>