A cylindrical oil barrel has a base diameter of 4 decimeters and a height of 5 decimeters measured from the inside. If gasoline weighs 0.75 kilograms per liter, how many kilograms of gasoline can this barrel hold?
一个圆柱形油桶，从里面量得底面直径4分米，高5分米．如果每升汽油重0.75千克，这个油桶可装汽油多少千克？
<gadget id="calculator">4 / 2</gadget>
<output>2</output>

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

<gadget id="calculator">3.14 * 4 * 5</gadget>
<output>62.8</output>

<gadget id="calculator">0.75 * 62.8</gadget>
<output>47.1</output>

<result>47.1</result>