A car transports goods to the city. When it goes there, it travels 45 kilometers per hour. It travels for 4 hours. When it returns, it only takes 3 hours. How many kilometers does it travel per hour when it returns?
一辆汽车往城里运货，去时每时行45千米，行了4小时，返回时只用了3小时，返回时每小时行多少千米？
<gadget id="calculator">4 / 3</gadget>
<output>4/3 = around 1.333333</output>

<gadget id="calculator">45 * (4/3)</gadget>
<output>60</output>

<result>60</result>