The clock struck 3 times at 3 o'clock, and it took 8 seconds to finish. So 7 o'clock knocked 7 times, how many seconds to finish knocking?
时钟3点时敲了3下，8秒钟敲完．那么7点钟敲了7下，几秒钟敲完？
<gadget id="calculator">3 - 1</gadget>
<output>2</output>

<gadget id="calculator">8 / 2</gadget>
<output>4</output>

<gadget id="calculator">7 - 1</gadget>
<output>6</output>

<gadget id="calculator">4 * 6</gadget>
<output>24</output>

<result>24</result>