A barrel of oil uses 12 liters, which is 3 liters more than the remaining (3/5). How many liters does this barrel of oil have?
一桶油，用去12升，比剩下的(3/5)多3升，原来这桶油有多少升．
<gadget id="calculator">12 - 3</gadget>
<output>9</output>

<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">9 / (3/5)</gadget>
<output>15</output>

<gadget id="calculator">15 + 12</gadget>
<output>27</output>

<result>27</result>