The quality of oil in barrel A is 1.5 times that of oil in barrel B. After 12.5 kg of oil in barrel A is poured into barrel B, the quality of the two barrels of oil is equal. How many kilograms does the B barrel of oil weigh?
A桶油的质量是B桶油的1.5倍，A桶油倒出12.5千克给乙桶后，两桶油的质量相等．原来B桶油重多少千克？
<gadget id="calculator">1.5 - 1</gadget>
<output>0.5</output>

<gadget id="calculator">2 / 0.5</gadget>
<output>4</output>

<gadget id="calculator">12.5 * 4</gadget>
<output>50</output>

<result>50</result>