There are two barrels of oil, A and B, with a total weight of 7.2 kg (excluding the weight of the barrel). After pouring (1/6) from barrel A into barrel B, the weight ratio of oil in barrels A and B is 5:3. How many kilograms of oil is in barrel A?
有甲、乙两桶油共重7.2千克(不含桶重)．从甲桶里倒出(1/6)到乙桶后，甲、乙两桶油的重量比是5：3．甲桶原来有油多少千克．
<gadget id="calculator">7.2 * 5</gadget>
<output>36</output>

<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">(1/6) * 5</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">(1/6) * 3</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">3 - (5/6) - (1/2)</gadget>
<output>5/3 = around 1.666667</output>

<gadget id="calculator">5 + (5/3)</gadget>
<output>20/3 = around 6.666667</output>

<gadget id="calculator">36 / (20/3)</gadget>
<output>27/5 = around 5.4</output>

<result>27/5 = around 5.4</result>