The distance between A and B is 990 kilometers. A bus and a truck drive to B at the same time. It is known that the speed of the passenger car is 55 km/h and the speed of the truck is 45 km/h. Think about how many kilometers away the truck is from point B when the bus arrives at point B?
甲、乙两城相距990干米，一辆客车和一辆货车同时开往乙城．已知客车的速度是55千米/时，货车的速度是45千米/时．想一想当客车到达乙地时，货车距离乙地还有多少千米？
<gadget id="calculator">990 / 55</gadget>
<output>18</output>

<gadget id="calculator">45 * 18</gadget>
<output>810</output>

<gadget id="calculator">990 - 810</gadget>
<output>180</output>

<result>180</result>