Nine of the kids in Gina's class are allergic to dairy, 6 are allergic to peanuts and 3 are allergic to both. If there are 32 kids in her class, how many aren't allergic to anything?
First subtract the number of kids who are allergic to each item from the total number of kids: 32 kids - 6 kids - 9 kids = <<32-6-9=17>>17 kids
Then add the number of kids who were double-counted because they're allergic to both things: 17 kids + 3 kids = <<17+3=20>>20 kids
#### 20