Class has 28 students. 23 like basketball. Also, 15 like baseball. 12 like both. How many students do not like either.

Answer 1

do it with Venn diagrams
Draw two intersecting circles, call one basketball, the other baseball.
put 12 in the intersection.
Look at the basketball circle, 12 of the 23 that like it have already been placed in that circle, put the remainder of 11 in the open part of basketball.

In the same way put 3 in the open part of baseball.
Adding up the 3 numbers in the circles, 11 + 12 + 3 = 26

But there were 28 students, so 2 are not in either circle.
so 2 don't like either.

Answer 2

12÷2=6
23-6=17basketball
15-6=9baseball
27+9=26
28-26=2