dog and a rabbit run a 3000-meter race. When the dog is 1000 meters away from the finish line, the rabbit is 2000 meters away from the finish line. If their speed remains the same, when the dog reaches the finish line, how far is the rabbit from the finish line?
狗兔进行3000米赛跑，狗离终点还有1000米时，兔离终点2000米．如果它们的速度不变，当狗到终点时，兔离终点多少米．
<gadget id="calculator">3_000 - 1_000</gadget>
<output>2_000</output>

<gadget id="calculator">3_000 - 2_000</gadget>
<output>1_000</output>

<gadget id="calculator">2_000 / 1_000</gadget>
<output>2</output>

<gadget id="calculator">3_000 / 2</gadget>
<output>1_500</output>

<gadget id="calculator">3_000 - 1_500</gadget>
<output>1_500</output>

<result>1_500</result>