Mr. Li deposits 50,000 yuan in the bank for two years, and gets back a total of 52,500 yuan of principal and interest when it matures. What is the annual interest rate of his deposit?
李老师在银行存款5万元，定期两年，到期一共取回本金和利息52500元，他存款的年利率是多少？
<gadget id="calculator">5 * 10_000</gadget>
<output>50_000</output>

<gadget id="calculator">52_500 - 50_000</gadget>
<output>2_500</output>

<gadget id="calculator">2_500 / 50_000 / 2</gadget>
<output>1/40 = around 0.025</output>

<result>1/40 = around 0.025</result>