There are 40 trains arriving on time on Wednesday. There are 10 trains that are delayed. What is the punctuality rate of trains at the station on this day
星期三正点到站的火车有40列．有10列火车误点．这一天车站火车的正点率是多少
<gadget id="calculator">40 + 10</gadget>
<output>50</output>

<gadget id="calculator">40 / 50</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">100 / 100</gadget>
<output>1</output>

<gadget id="calculator">(4/5) * 1</gadget>
<output>4/5 = around 0.8</output>

<result>4/5 = around 0.8</result>