Answer:
40 students participate only in music.
Explanation:
When you add the two groups together, you get 50 + 60 = 110. But there are only 100 students, so 10 of them must have been counted twice (they do music AND sports. Put 10 in the middle part of the Venn diagram (image2).
Subtract 10 from each of the two groups to find the number of students taking only one of the two subjects. For example, there are 50 music students, but 10 of them also do sports, so 50 - 10 = 40 students do only music. (There are 60 - 10 = 50 students who participate only in sports.) (image3).