The turnover of Starlight Hotel last month was 420,000 yuan. If the hotel pays business tax at 5% of the turnover, what is the net income of last month?
星光饭店上个月的营业额是42万元，如果饭店按营业额的5%缴纳营业税后，上个月的纯收入是多少万元．
<gadget id="calculator">5 / 100</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">1 - (1/20)</gadget>
<output>19/20 = around 0.95</output>

<gadget id="calculator">42 * (19/20)</gadget>
<output>399/10 = around 39.9</output>

<result>399/10 = around 39.9</result>