In the shuttlecock kicking activity, each person in a certain class kicks 6 times on average, if only girls kick, the average is 15 times per person, if only boys kick, how many times per person on average.
踢毽子活动中，某班平均每人踢6下，如果只是女生踢，平均每人15下，如果只是男生踢，平均每人多少下．
<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">1 / 15</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">(1/6) - (1/15)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 / (1/10)</gadget>
<output>10</output>

<result>10</result>