A person is traveling along a bus line at a speed of 3 kilometers per hour. Every 8 minutes a bus catches up with him, and every 6 minutes he encounters an oncoming bus. The buses are separated by the same distance and the speed is Also, how many kilometers does the bus travel per hour?
某人以每小时3千米的速度沿公交线路前进，每8分钟有一辆公交车从后面追上它，每6分钟又与迎面而来的公交车相遇一次，公交车相隔的路相同，速度也一样，公交车每小时行多少千米．
<gadget id="calculator">6 / 8</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">(3/4) * 3</gadget>
<output>9/4 = around 2.25</output>

<gadget id="calculator">3 + (9/4)</gadget>
<output>21/4 = around 5.25</output>

<gadget id="calculator">1 - (3/4)</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(21/4) / (1/4)</gadget>
<output>21</output>

<result>21</result>