Math Riddles

Question: When Tommy was 10 years old his sister Suzy was half his age. Now that Tommy is 50 years old how old is his sister Suzy?

Question: What's the angle between minute hand and hour hand at a quarter past three?

Question: What is half of 2+2?

Question: What number do you get when you multiply all of the numbers on a telephone's number pad?

Question: Three guests check into a hotel room. The clerk says the bill is $30, so each guest pays $10. Later the clerk realizes the bill should only be $25. To rectify this, he gives the bellhop $5 to return to the guests. On the way to the room, the bellhop realizes that he cannot divide the money equally. As the guests didn't know the total of the revised bill, the bellhop decides to just give each guest $1 and keep $2 for himself. Each guest got $1 back: so now each guest only paid $9; bringing the total paid to $27. The bellhop has $2. And $27 + $2 = $29 so, if the guests originally handed over $30, what happened to the remaining $1?