After a math competition with less than 50 participants, Mr. Wang said: "There are (1/6) people who won the first prize, (1/3) people won the second prize, and (2/7) people won the first prize." won the third prize. The rest won the prize of excellence, how many people won the prize of excellence."
在一次不到50人的数学竞赛后，王老师说："有(1/6)的人获一等奖，有(1/3)的人获二等奖，有(2/7)的人获三等奖．其余的获优胜奖，获优胜奖的有多少人．"
<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">1 - (1/6) - (1/3) - (2/7)</gadget>
<output>3/14 = around 0.214286</output>

<gadget id="calculator">42 * (3/14)</gadget>
<output>9</output>

<result>9</result>