The turnover of the shopping mall in August was 650,000 yuan, which increased (1/5) in September compared to August. If the turnover is paid at 5% of the increase, how much is the business tax payable in September?
商场八月份的营业额是65万元，九月份比八月份增加了(1/5)，如果按增加额的5%缴纳营业额，九月份应缴纳营业税多少万元？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 + (1/5)</gadget>
<output>6/5 = around 1.2</output>

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

<gadget id="calculator">65 * (6/5) * (1/20)</gadget>
<output>39/10 = around 3.9</output>

<result>39/10 = around 3.9</result>