Dad buys 3,000 yuan of three-year treasury bonds with an interest rate of 4.5%. How much will he get in principal and interest after three years?
爸爸购买利率是4.5%的三年国库券3000元，三年后可得本息多少元．
<gadget id="calculator">4.5 / 100</gadget>
<output>0.045</output>

<gadget id="calculator">3_000 * 0.045 * 3</gadget>
<output>405</output>

<gadget id="calculator">405 + 3_000</gadget>
<output>3_405</output>

<result>3_405</result>