student that like swimming = x + 2

where 2 is the number of students who like reading, dancing and swimming. To find x from the venn diagram of swimming

6 +3 + 2 + x = 16

11 + x = 16

x = 16 - 11 = 5

no. of students that like dancing and swimming

x + 2 = 5 + 2 = 7