Riddle #99

Question: How many people do you need to have the odds be in favor (at least 50% chance) of two people having the same birthday?

Question: When is 99 more than 100?

Question: You have a glass of water that looks about half full. How can you tell, only using the glass of water itself, if the glass is half full or not?

The glass is a right cylinder.

Question: Mr. Smith has 4 daughters. Each of his daughters has a brother.

How many children does Mr. Smith have?

Question: Nathan has math 4 times a week. If he has math 8:00 Monday, 9:20 on Tuesday, 10:40 on Wednesday, and 1:20 on Friday, when does Nathan have math on Thursday?

Question: There is a 5 gallon and a 3 gallon box. You also have a hose with unlimited water. How are you gonna make the 5 gallon have 4 gallons using your items? (You do not know the exact measure measurements of a gallon)