A class of 30 students was asked what they did on their winter holiday.
20 students said that they went skating.
9 students said that they went skiing.
Exactly 5 students said that they went skating and went skiing.
How many students did not go skating and did not go skiing?
+1005 5 people are in the middle.
Thus 20-5 only went skating, 9-5 only went skiing.
30 -5 - 15- 4 = 6
Thus 6 people did neither.
If you don't understand anything feel free to ask!
