Math Riddles

Question: someone came into my shop and stole 100 dollars from the register without my knowledge. the person came back 5 minutes later with the same 100 dollars and bought 70 dollars in items and i gave him back 30 dollars change. How much did i lose?

Question: There are 2 brother's, the oldest is 4 yrs old. The little brother Is 1/2 his age. When the big brother is 100 how old will the little brother be?

Question: If I am buying 9 for $1, 18 for $2, 125 for $3, and 1222 for $4, then what am I buying?

Question: How do you make 9 by just 3 toothpicks?

Question: A man lives in an apartment building on the 100th floor. He rides the elevator all the way down to floor 1 every morning then all the way up to floor 100 every evening. The elevator is coin-operated. It costs $0.25 per floor for floors 1-25, $0.50 per floor for floors 26-50, $0.75 per floor for floors 51-75, and $1.00 per floor for floors 75-100. How much money does the man spend each day riding the elevator?