A certain school organizes summer vacation tours, the total number of people who go to Beijing (1/4), those who go to Zhangjiajie (2/5), and the rest go to Hainan. What percentage of the total number of tourists go to Hainan?
某校暑假组织旅游，去北京旅游的占总人数的(1/4)，去张家界旅游的占总人数的(2/5)，剩下的去海南旅游．去海南旅游的占总人数的几分之几？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (1/4) - (2/5)</gadget>
<output>7/20 = around 0.35</output>

<result>7/20 = around 0.35</result>