The distance between A and B is 60 kilometers. Zhang Ming departs from A to B at 8:00. The average speed of the first half of the time is 1 km per minute, and the average speed of the second half of the time is 0.8 km per minute. How long does it take Zhang Ming to arrive B land?
甲乙两地相距60千米，张明8点从甲地出发去乙地，前一半时间平均速度为每分钟1千米，后一半时间平均速度为每分钟0.8千米，张明经过多少时间到达乙地？
<gadget id="calculator">1 + 0.8</gadget>
<output>1.8</output>

<gadget id="calculator">60 / 1.8</gadget>
<output>33.333333</output>

<gadget id="calculator">33.333333 * 2</gadget>
<output>66.666666</output>

<result>66.666666</result>