There is some oil in an oil drum. If the amount of oil is doubled, the weight of the drum and the oil will be 38 kg; if the amount of oil is quadrupled, the total weight of the oil and the drum will be 46 kg. How many kilograms of oil are there in the oil barrel?
一只油桶里有一些油，如果把油加到原来的2倍，油桶连油重38千克；如果把油加到原来的4倍，这时油和桶共重46千克．原来油桶里有油多少千克？
<gadget id="calculator">46 - 38</gadget>
<output>8</output>

<gadget id="calculator">8 / 2</gadget>
<output>4</output>

<result>4</result>