The distance between A and B is 570km, and a small car travels 285km in 3 hours. At this speed, to reach City B before 15:00, when will this car leave City A at least?
甲、乙两城相距570km，一辆小车3时行了285km．照这样的速度，要赶在15：00之前到达乙城，这辆小车至少在什么时候从甲城出发？
<gadget id="calculator">285 / 3</gadget>
<output>95</output>

<gadget id="calculator">570 / 95</gadget>
<output>6</output>

<gadget id="calculator">15 - 6</gadget>
<output>9</output>

<result>9</result>