Out of 30 students, if you add up 11, 16, and 3, you get 30. Which means there is no remainder and there are no students that did not like either sport.
the answer is 5 since the sides are kinda equal to each other it looks like
Y = x + 4
y = 3x + 6
set them equal..
x + 4 = 3x + 6 <==