During Arbor Day, an average of 6 trees were planted per person in a certain class. If it is done by girls only, each person should plant 15 trees; if it is done by male students, how many trees should each person plant.
植树节时，某班平均每人植树6棵．如果只由女生完成，每人应植树15棵；如果由男同学完成，每人应植树多少棵．
<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>