There are 10 buses parked at a station, and one is dispatched every 5 minutes. After the first bus leaves, how many minutes later the last bus can leave.
在一个车站停有10辆公共汽车，每隔5分钟发一辆，第一辆车开出之后，再过多少分最后一辆车才能出发．
<gadget id="calculator">10 - 1</gadget>
<output>9</output>

<gadget id="calculator">9 * 5</gadget>
<output>45</output>

<result>45</result>