A barrel of oil weighs 25.1 kilograms in total. After using 2/3 of the oil, the weight of the barrels is still 9.1 kilograms. How many kilograms of oil does this barrel contain?
一桶油连桶共重25.1千克，用去油的(2/3)后，连桶还重9.1千克，这个油桶有油多少千克？
<gadget id="calculator">25.1 - 9.1</gadget>
<output>16</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">16 / (2/3)</gadget>
<output>24</output>

<result>24</result>