In a city, the number of middle school students is 1/5 of the number of residents, and the number of college students is 1/4 of the number of middle school students. So what percentage of the number of residents are the number of science and engineering students who account for 2/5 of the total number of college students?
在一座城市中，中学生数是居民的(1/5)，大学生是中学生数的(1/4)，那么占大学生总数的(2/5)的理工科大学生是居民数的几分之几？
<gadget id="calculator">1 / 50</gadget>
<output>1/50 = around 0.02</output>

<result>1/50 = around 0.02</result>