6 riddles were guessed by 50 people, and a total of 178 guesses were correct. It is known that each person guesses at least 2 correctly, and there are 16 people who guess 2 correctly, 9 people who guess 4 correctly, and as many people who guess 3 correctly as 5, then how many people guess all 6 correctly? people.
6条谜语让50人猜，共猜对了178条次．已知每人至少猜对2条，且猜对2条的有16人，猜对4条的有9人，猜对3条和5条的人数一样多，那么6条全猜对的有多少人．
<gadget id="calculator">2 * 16</gadget>
<output>32</output>

<gadget id="calculator">4 * 9</gadget>
<output>36</output>

<gadget id="calculator">25 * 6</gadget>
<output>150</output>

<gadget id="calculator">150 - 178</gadget>
<output>-28</output>

<gadget id="calculator">32 + 36 + (-28)</gadget>
<output>40</output>

<gadget id="calculator">2 * 6</gadget>
<output>12</output>

<gadget id="calculator">12 - 3 - 5</gadget>
<output>4</output>

<gadget id="calculator">40 / 4</gadget>
<output>10</output>

<gadget id="calculator">2 * 10</gadget>
<output>20</output>

<gadget id="calculator">25 - 20</gadget>
<output>5</output>

<result>5</result>