The distance between A and B is 100 kilometers. Zhang Xian starts from A by motorcycle, and Li drives a car to start from A one hour later. Both of them arrive at B at the same time. The motorcycle starts at a speed of 50 km/h and decelerates to 40 km/h halfway. The speed of the car is 80 km/h. The car once stopped for 10 minutes on the way, so how many hours after Zhang's motorcycle decelerated?
甲和乙两地相距100千米，张先骑摩托车从甲出发，1小时后李驾驶汽车从甲出发，两人同时到达乙地．摩托车开始速度是50千米/小时，中途减速为40千米/小时．汽车速度是80千米/小时．汽车曾经在途中停驶10分钟，那么张驾驶的摩托车减速时在他出发后的多少小时．
<gadget id="calculator">29 / 12</gadget>
<output>29/12 = around 2.416667</output>

<gadget id="calculator">40 * (29/12)</gadget>
<output>290/3 = around 96.666667</output>

<gadget id="calculator">100 - (290/3)</gadget>
<output>10/3 = around 3.333333</output>

<gadget id="calculator">50 - 40</gadget>
<output>10</output>

<gadget id="calculator">(10/3) / 10</gadget>
<output>1/3 = around 0.333333</output>

<result>1/3 = around 0.333333</result>