A barrel of oil weighs 15.4 kilograms. After half of the oil is poured out, the weight of the barrel is 8.6 kilograms. How many kilograms does the barrel weigh?
一桶油连桶重15.4千克，倒出一半油后，连桶重8.6千克，桶重多少千克？
<gadget id="calculator">15.4 - 8.6</gadget>
<output>6.8</output>

<gadget id="calculator">6.8 * 2</gadget>
<output>13.6</output>

<gadget id="calculator">15.4 - 13.6</gadget>
<output>1.8</output>

<result>1.8</result>