It takes 8 hours for a passenger ship to travel from port A to port B. It is known that it travels 30 kilometers per hour, and it takes 6 hours to return. How many kilometers per hour does it travel on average?
一艘客轮从甲港到乙港要航行8小时，已知它每小时航行30千米，返回时用了6小时，返回时平均每小时航行多少千米？
<gadget id="calculator">8 / 6</gadget>
<output>4/3 = around 1.333333</output>

<gadget id="calculator">30 * (4/3)</gadget>
<output>40</output>

<result>40</result>