The whole (2/5) of a barrel of oil is poured out for the first time, and the whole (1/3) is poured out for the second time, leaving (12/5) kilograms. How many kilograms does this barrel of oil originally have? (solution by equation)
一桶油第一次倒出全部的(2/5)，第二次倒出全部的(1/3)，还剩(12/5)千克，这桶油原来有多少千克？(用方程解)
<gadget id="calculator">12 / 5</gadget>
<output>12/5 = around 2.4</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (2/5) - (1/3)</gadget>
<output>4/15 = around 0.266667</output>

<gadget id="calculator">(12/5) / (4/15)</gadget>
<output>9</output>

<result>9</result>