Can you solve the "Brain Teasers"

This is something new that I have not done on here before but recently I found myself getting more involved in puzzles and these small brain teasers. I figured i would put a few out there and see how this goes or if anyone even likes them anymore. If this becomes a hit maybe we will do random giveaways and even possible daily challenges.

Here are a few that I ran across today some are easy but not all are going to be:

No: 1
14 of the kids in the class are girls. 8 of the kids wear blue shirts. 2 of the kids are neither girls or wear a blue shirt. If 5 of the kids are girls who wear blue shirts how many kids are in the class?

No:2

No:3

No:4

No:5

These images are not mine and were used from multiple brain teaser sites.