A car travels 60 kilometers per hour from place A to place B. It arrives 1 hour earlier than planned, and travels 40 kilometers per hour when it returns, and arrives 1 hour later than planned. How many hours did it arrive at?
一辆汽车从甲地到乙地，去时每小时行60千米，比计划早到1时，返回时每小时行40千米，比计划迟到1小时，原计划几小时到达？
<gadget id="calculator">60 - 40</gadget>
<output>20</output>

<gadget id="calculator">2 / 20</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">40 * (1/10)</gadget>
<output>4</output>

<gadget id="calculator">4 + 1</gadget>
<output>5</output>

<result>5</result>