Four friends - Alex, Brian, Charlie, and David - have different favorite colors: Red, Blue, Green, and Yellow. Alex does not like Red or Blue. Brian's favorite color is not Green. Charlie likes Blue. What is David's favorite color?
Four friends, A, B, C, and D, have different pets: a dog, a cat, a bird, and a fish. A does not own the dog or the cat. B owns the bird. C does not own the fish. Which pet does D own?