Dogs in the GoodDog Obedience School win a blue ribbon for learning how to sit, a green ribbon for learning how to roll over, and a white ribbon for learning how to stay. There are dogs in the school.
have blue ribbons, have green ribbons, and have white ribbons.
have a blue ribbon and a green ribbon; have a green ribbon and a white ribbon; have a blue ribbon and a white ribbon.
have all three ribbons.
How many dogs have not learned any tricks?
Just a little more info? Cause We can't solve it without it-
If you would like us to answer for you~ make another forum explaining more :3