Puzzle #18: IIT Students and Hats Puzzle | Google

Puzzle #17: 100 Doors Puzzle | Google | Adobe | Amazon | Oracle

Puzzle #16: Age of 3 Children | Google

Puzzle #15: Prisoners and Hats Puzzle | Google

Puzzle #14: 13 Caves And A Thief Puzzle | Google

Puzzle #13: 10 Coins Puzzle | Google | Yahoo

Puzzle #12: Possible Paths across a Rectangular Grid | Google

Puzzle #11: Prove that p^2 – 1 is Divisible by 24 | Google