There are 35 students in a class, and each student participates in at least one extracurricular activity group in English group, Chinese group and math group. Now it is known that there are 17 students in English group, 30 students in Chinese group and 13 students in math group. If five students participated in all three groups, how many students only participated in one group?

solve

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There are 0/7 people in English group, 30 people in Chinese group and 0/3 people in Mathematics group.

17+30+ 13=60

(Every student should join at least one tutoring group)

60-35=25

25 people (participants in groups 2 and 3)

There are five people in all three groups (60-35=25

Subtract once),

5*2= 10 (the other two times)

25- 10= 15 (the rest are repeated twice, that is, the number of participants in the two groups)

1 ***35 people: 5 people in 3 groups, 2 groups 15 people, 1 group 35-5- 15 = 15 people.

Answer: There are 15 students who only participated in one group.