A cylindrical oil barrel with a base radius of 20 cm contains oil to a depth of 30 cm. It is known that the ratio of the oil in the oil barrel to the volume of the oil barrel is 3:5, what is the volume of the oil barrel?
一个圆柱形状的油桶，底面半径是20厘米，里面装了30厘米深的油．已知油桶里的油与油桶的容积的比是3：5，这个油桶的容积是多少？
<gadget id="calculator">20 ** 2</gadget>
<output>400</output>

<gadget id="calculator">5 / 3</gadget>
<output>5/3 = around 1.666667</output>

<gadget id="calculator">3.14 * 400 * 30 * (5/3)</gadget>
<output>62_800</output>

<result>62_800</result>