The price of "World Olympiad Special Issue" is 40 yuan per book, and the competition organizing committee decided to sell it to students participating in the "World Olympiad" at a 10% discount, but after the discount, an additional 5% is required as tax. So, how much does the participating students actually need to buy the special issue?
《世界奥数专刊》的标价是40元/本，大赛组委会决定减价10%出售给参加"世奥赛"的学生，但打了折扣后需附加5%作为税金．那么，参赛学生购买专刊实际需要多少元．
<gadget id="calculator">10 / 100</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 - (1/10)</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">5 / 100</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">1 + (1/20)</gadget>
<output>21/20 = around 1.05</output>

<gadget id="calculator">40 * (9/10) * (21/20)</gadget>
<output>189/5 = around 37.8</output>

<result>189/5 = around 37.8</result>