A car drives from Dongcheng to Xicheng, travels 45 kilometers per hour, reaches Xicheng in 6 hours, and returns from Xicheng to Dongcheng in only 5 hours, which is an average of more kilometers per hour than driving from Dongcheng to Xicheng.
一辆汽车从东城开往西城，每小时行45千米，6小时到达西城，从西城返回东城只用了5小时，比从东城开往西城平均每小时多行多少千米．
<gadget id="calculator">6 / 5</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">45 * (6/5)</gadget>
<output>54</output>

<gadget id="calculator">54 - 45</gadget>
<output>9</output>

<result>9</result>