50 students were asked, and only 5 said that they did not like apples or bananas.
This means that 45 students like either apples or bananas, or both of them. We will call these 45 students, the group of "45".
We also know that, between these 45 students there are 36 who like apples and 30 that like bananas. This imply that, 45-36=9 students do not like apples, and 45-30=15 students do not like bananas.
Then, there are 15 students within the group of "45" that do not like bananas, and 9 students within the group of "45" that do not like apples. This means that 9+15=24 students within the group of "45" only like bananas or apples. The rest of them, 45-24= 26 like both apples and bananas.
Divide the nonagon radially into 9 congruent, equilateral isosceles triangle. Each triangle has vertex angle of 360°/9 = 40°. Interior angle of polygon = 180°-40° = 140°. Sum of interior angles = 9(140°) = 1260°
