A horse can run 6 steps in the time that a dog runs 4 steps. A horse runs 3 steps as far as a dog runs 6 steps. Now the dog has run 600 meters before the horse starts to chase the dog. How many meters can the horse run to catch up with the dog?
狗跑4步的时间马能跑6步．马跑3步的距离相当于狗跑6步的距离．现在狗已跑出600米，马才开始追狗，马跑多少米可以追上狗？
<gadget id="calculator">36 - 12</gadget>
<output>24</output>

<gadget id="calculator">600 / 24</gadget>
<output>25</output>

<gadget id="calculator">36 * 25</gadget>
<output>900</output>

<result>900</result>