There are two barrels of oil, A and B. Originally, the weight of oil in barrel A is 80% of that of barrel B. When 10 kg of oil is taken out from barrel A and poured into barrel B, the weight of oil in barrel A is 60% of that of barrel B. How many kilograms does a drum of oil weigh?
甲、乙两桶油，原来甲桶油重是乙桶油的80%，当甲桶取出10千克油倒入乙桶，这时甲桶油重是乙桶的60%．原来甲桶油重多少千克．
<gadget id="calculator">4 + 5</gadget>
<output>9</output>

<gadget id="calculator">4 / 9</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">3 + 5</gadget>
<output>8</output>

<gadget id="calculator">3 / 8</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">(4/9) - (3/8)</gadget>
<output>5/72 = around 0.069444</output>

<gadget id="calculator">10 / (5/72)</gadget>
<output>144</output>

<gadget id="calculator">144 * (4/9)</gadget>
<output>64</output>

<result>64</result>