A 10-second advertisement is inserted and broadcast once a day. A total of 178,500 yuan is paid for three weeks. How much is the average per second?
插播10秒广告，每天播出一次，三周共付人民币17.85万元，平均每秒多少元？
<gadget id="calculator">10 * 7 * 3</gadget>
<output>210</output>

<gadget id="calculator">17.85 / 210</gadget>
<output>0.085</output>

<result>0.085</result>