The school surveyed the students' preference for teaching subjects. Among the students in Class 1 of five years, those who liked sports accounted for (4/5), those who liked art accounted for (3/4), and those who didn't like sports or art accounted for (1/20). What percentage of the class are those who like sports and art?
学校调查学生喜欢科任课的情况，五年一班同学中喜欢体育的占(4/5)，喜欢美术的占(3/4)，体育、美术都不喜欢的占(1/20)，既喜欢体育又喜欢美术的占全班的几分之几？
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">(4/5) + (3/4)</gadget>
<output>31/20 = around 1.55</output>

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

<gadget id="calculator">1 - (1/20)</gadget>
<output>19/20 = around 0.95</output>

<gadget id="calculator">(31/20) - (19/20)</gadget>
<output>3/5 = around 0.6</output>

<result>3/5 = around 0.6</result>