Aunt Zhang lives in the suburbs. On weekends, she takes a bus from home to Huamei Electric City to buy a refrigerator. When going there, the speed of the bus was 60 km/h, and it took 2 hours. It took 3 hours to come back. What was the speed of the bus when she returned?
张阿姨家住在郊区，周末她从家公共汽车去华美电器城买电冰箱．去时公交车的速度是60千米/小时，用了2小时．回来时用了3小时．她返回时公交车的速度是多少？
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">60 * (2/3)</gadget>
<output>40</output>

<result>40</result>