There are 100 people at lunch. The fruits available for lunch are blueberries, raspberries, or blackberries.
59 people have blueberries, 27 have raspberries, and 64 have blackberries.
25 people have both blueberries and raspberries; 12 people have raspberries and blackberries; 28 people have blackberries and blueberries.
10 people have all three fruits.
How many people have no fruit at all?
We can draw in a Venn Diagram with 3 circles. We first label the circles blueberries, raspberries, and blackberries. In the middle where all the circles intersect it, we write the number 10. Then, we label everything else.
All fruits - 10
Blueberries and raspberries - 15
Raspberries and blackberries - 2
Blackberries and blueberries - 18
Just blueberries - 16
Just raspberries - none
Just blackberries - 34
Adding these all up we get 95. Subtracting that from 100 we get that 5 people had no fruit at all.
(P.S. They should have had fruit. Fruit is good for you!)