A barrel of oil weighs 180 kg, and after selling 150 kg of oil, 10 kg of oil remains. How many kilograms does the oil barrel weigh?
一桶油连桶重180千克，卖出150千克油后还剩10千克油．问油桶重多少千克？
<gadget id="calculator">150 + 10</gadget>
<output>160</output>

<gadget id="calculator">180 - 160</gadget>
<output>20</output>

<result>20</result>