My mother deposited 20,000 yuan in the bank for my education fee for one year, with an annual interest rate of 3.5%. After paying the interest tax (20% of the interest) when due, how much is the total amount of the principal and the after-tax interest?
妈妈给我在银行存入20000元的教育费，定期一年，年利率是3.5%，到期缴纳利息税(利息的20%)后，本金和税后利息一共是多少元？
<gadget id="calculator">3.5 / 100</gadget>
<output>0.035</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">20_000 * 0.035 * 1 * (4/5)</gadget>
<output>560</output>

<gadget id="calculator">20_000 + 560</gadget>
<output>20_560</output>

<result>20_560</result>