A certain class of students took a math test with three questions in total. As a result, 38 people got the first question right, 41 people got the second question right, and 27 people got the third question right. There were 32 people who got the first and second questions right, 21 people who got the first and third questions right, 20 people who got the second and third questions right, 17 people who got all right, and none who got all wrong. How many people are in the class?
某班学生在一次共出了三道题的数学测验中，结果做对第一题的有38人，做对第二题的有41人，做对第三题的有27人，同时做对第一、二题的有32人，做对一、三两题的有21人，做对第二、三两题的有20人，全对的有17人，没有全错的．求全班人数是多少人？
<gadget id="calculator">38 + 41 + 27</gadget>
<output>106</output>

<gadget id="calculator">32 + 21 + 20</gadget>
<output>73</output>

<gadget id="calculator">106 - 73</gadget>
<output>33</output>

<gadget id="calculator">33 + 17</gadget>
<output>50</output>

<result>50</result>