The distance between A and B ports is 154 kilometers. It takes 7 hours and 20 minutes for a ship to sail upstream from A port to B port. When it comes back, it only takes 4 hours and 40 minutes. The ship goes back and forth between A and B. How many kilometers per hour are you driving on average?
甲、乙两港相距154千米，一艘轮船从甲港逆水驶往乙港用了7小时20分，回来时顺水航行，只用4小时40分，这艘轮船往返甲、乙两港，往返时平均每小时行驶多少千米？
<gadget id="calculator">22 / 3</gadget>
<output>22/3 = around 7.333333</output>

<gadget id="calculator">14 / 3</gadget>
<output>14/3 = around 4.666667</output>

<gadget id="calculator">(22/3) + (14/3)</gadget>
<output>12</output>

<gadget id="calculator">2 / 12</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">154 * (1/6)</gadget>
<output>77/3 = around 25.666667</output>

<result>77/3 = around 25.666667</result>