At the beginning of 2008, a snowstorm occurred in the south of my country. The power line in a certain place was broken. The maintenance team of the power supply bureau had to rush to repair it. The repair personnel rode motorcycles at a speed of 640 meters per minute. The speed of 1000 meters per minute is catching up, and the motorcycle will arrive at the destination in 25 minutes. If the repair vehicle and the motorcycle are to arrive at the same time, how long should the repair vehicle leave after the motorcycle departs?
2008年初，我国南方发生雪灾，某地电线被压断，供电局的维修队要前住抢修，抢修人员骑摩托车以每分钟640米的速度先出发，抢修车运载抢修设备过一段时间以每分钟1000米的速度追赶，摩托车25分钟后到达目的地，若要抢修车与摩托车同时到达，抢修车应在摩托车出发多久后出发？
<gadget id="calculator">1_000 * 25</gadget>
<output>25_000</output>

<gadget id="calculator">640 * 25</gadget>
<output>16_000</output>

<gadget id="calculator">25_000 - 16_000</gadget>
<output>9_000</output>

<gadget id="calculator">9_000 / 1_000</gadget>
<output>9</output>

<result>9</result>