Primary school students in a certain district held two mathematics competitions, and the number of students who passed the first time was 3 times more than the number who failed; the number of students who passed the second time increased by 5, which was exactly 6 times the number of people who failed. Ask how many students participated in the mathematics competition.
某区小学生进行两次数学竞赛，第一次及格的比不及格的3倍多4人；第二次及格人数增加了5人，正好是不及格人数的6倍．问共有多少学生参加数学竞赛．
<gadget id="calculator">5 * 6</gadget>
<output>30</output>

<gadget id="calculator">30 - 0</gadget>
<output>30</output>

<gadget id="calculator">4 + 5 + 30</gadget>
<output>39</output>

<gadget id="calculator">6 - 3</gadget>
<output>3</output>

<gadget id="calculator">39 / 3</gadget>
<output>13</output>

<gadget id="calculator">4 * 13</gadget>
<output>52</output>

<gadget id="calculator">52 + 4</gadget>
<output>56</output>

<result>56</result>