Someone rides a motorcycle to chase a tractor. If you chase at a speed of 30 kilometers per hour, it will take 30 minutes to catch up. If you chase at a speed of 36 kilometers per hour, it will take 20 minutes to catch up. If you chase at a speed of 54 kilometers per hour, how many minutes will it take to catch up?
某人骑摩托车去追拖拉机．如果以30千米的时速去追，那么需30分钟追上，如果以36千米的时速去追，那么需20分钟追上．如果以54千米的时速去追，那么需要多少分钟追上？
<result>10</result>