There are a total of 250 electric poles from the power plant to the downtown area, and the distance between every two adjacent electric poles is 30 meters. How far is it from the power plant to downtown?
从发电厂到闹市区一共有250根电线杆，每相邻两根电线杆之间是30米．从发电厂到闹市区有多远？
<gadget id="calculator">250 - 1</gadget>
<output>249</output>

<gadget id="calculator">30 * 249</gadget>
<output>7_470</output>

<result>7_470</result>