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