total of 36 people in a class bought pencils, a total of 50 pencils, some bought 1, some bought 2, and some bought 3. If twice as many people buy 1 pencil as the rest, how many people buy 2 pencils?
某班共36人都买了铅笔，共买了50支，有人买了1支，有人买了2支，有人买了3支．如果买1支的人数是其余人数的2倍，则买2支铅笔的人数是多少．
<gadget id="calculator">1 + 2</gadget>
<output>3</output>

<gadget id="calculator">36 / 3</gadget>
<output>12</output>

<gadget id="calculator">12 * 2</gadget>
<output>24</output>

<gadget id="calculator">12 * 3</gadget>
<output>36</output>

<gadget id="calculator">36 - 50</gadget>
<output>-14</output>

<gadget id="calculator">24 + (-14)</gadget>
<output>10</output>

<gadget id="calculator">3 - 2</gadget>
<output>1</output>

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

<result>10</result>