The students of Class 5 and 1 went on a spring outing and spent 10 hours together. Among them, the time spent on the road accounts for (1/5), the time for eating and resting accounts for (3/10), and the rest is the time for sightseeing. What percentage of the time for sightseeing?
五1班学生去春游，共用去10小时．其中路上用去的时间占(1/5)，吃饭与休息时间共占(3/10)，剩下的是游览时间，游览时间占几分之几？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">3 / 10</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">1 - (1/5) - (3/10)</gadget>
<output>1/2 = around 0.5</output>

<result>1/2 = around 0.5</result>