A and B are 40 kilometers apart. A starts for 1.5 hours, and B starts again. A is behind and B is in front. The two are walking in the same direction. A's speed is 8 kilometers per hour, and B's speed is 6,000 kilometers per hour. M, how many hours does A catch up with B after departure?
甲乙两人相距40千米，甲先出发1.5小时，乙再出发，甲在后乙在前，两人同向而行，甲的速度为每小时8千米，乙的速度为每小时6千米，甲出发后几小时追上乙？
<gadget id="calculator">8 * 1.5</gadget>
<output>12</output>

<gadget id="calculator">40 - 12</gadget>
<output>28</output>

<gadget id="calculator">8 - 6</gadget>
<output>2</output>

<gadget id="calculator">28 / 2</gadget>
<output>14</output>

<gadget id="calculator">14 + 1.5</gadget>
<output>15.5</output>

<result>15.5</result>