Grandpa Li bought 2,000 yuan of government bonds in 2005, fixed for three years, and the annual interest rate of the three-year government bonds is 3.32%. And buying government bonds can avoid paying 20% interest tax, so how much can Grandpa Li avoid paying interest tax?
李爷爷2005年买了2000元国债，定期三年，三年国债的年利率为3.32%．而买国债可以免交20%的利息税，那么李爷爷可以免交利息税多少元？
<gadget id="calculator">3.32 / 100</gadget>
<output>0.0332</output>

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

<gadget id="calculator">2_000 * 0.0332 * 3 * (1/5)</gadget>
<output>39.84</output>

<result>39.84</result>