The uncle buys back a batch of apples with 4000 yuan, and then sells them at 150% of the purchase price. According to the regulations, the uncle should pay tax at 5% of the turnover. How much tax should the uncle pay in this transaction.
叔叔用4000元购回一批苹果，然后按进价的150%出售，根据规定叔叔应按营业额的5%交纳税款，叔叔在这次买卖中应交纳税款多少元．
<gadget id="calculator">150 / 100</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">4_000 * (3/2)</gadget>
<output>6_000</output>

<gadget id="calculator">6_000 - 4_000</gadget>
<output>2_000</output>

<gadget id="calculator">5 / 100</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">2_000 * (1/20)</gadget>
<output>100</output>

<result>100</result>