MATH RIDDLE

Question: TWO THEIFS HAD ROBED GOLD COINS IN ONE HOUSE...! THEY WANT 2 SHARE EQUALLY...! BUT ONE WAS LEFT...! SO THEY ADDED ANOTHER PERSON NOW 3 SHARED AGAIN ONE COIN WAS REMAINING...! 4,5,6..! AT LAST 7MEMBERS SHARED EQUALLY...! THAT MEANS HOW MANY COINS THEY ROBBED...?;-)

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: 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)

Question: I'm 10 years old my brothers half my age now I'm 100 years old how old is my brother now?

Question: What are the next two letters in the following series and why? WATNTLITFS__