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 100 dogs in the school.
* 62 have blue ribbons, 65 have green ribbons, and 50 have white ribbons.
* 35 have a blue ribbon and a green ribbon; 23 have a blue ribbon and a white ribbon; 31 have a green ribbon and a white ribbon.
* 15 have all three ribbons.
Fill in the Venn diagram.
