A barrel of oil weighs 150 kilograms. After half of the oil is sold, another 10 kilograms are sold. At this time, the remaining oil and the barrel weigh 75 kilograms. How much does the barrel weigh?
一桶油重150千克，卖出油的一半后，又卖出10千克，这时剩下的油和桶共重75千克，这个桶重多少千克？
<gadget id="calculator">150 - 75 - 10</gadget>
<output>65</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">65 / (1/2)</gadget>
<output>130</output>

<gadget id="calculator">150 - 130</gadget>
<output>20</output>

<result>20</result>