If the puzzle you solved before you solved the puzzle you solved after you solved the puzzle you solved before you solved this one, was harder than the puzzle you solved after you solved the puzzle you solved before you solved this one, was the puzzle you solved before you solved this one harder than this one?

I live on Sunset Boulevard, where there are 6 houses on my side of the block.  The house numbers are consecutive even numbers.  The sum of all 6 house numbers is 8790.  You don’t know which block I live on, and it’s a long street, but I will tell you that I live in the lowest number on my side of the block.  What’s my address?

If you add the age of a man to the age of his wife, the result is 91.  He is now twice as old as she was when he was as old as she is now.

How old is the man and his wife?

Three spies, suspected as double agents, speak as follows when questioned:

Albert: “Bertie is a mole.”
Bertie: “Cedric is a mole.”
Cedric: “Bertie is lying.”

Assuming that moles lie, other agents tell the truth, and there is just one mole among the three, determine:

1.) Who is the mole?
2.) If, on the other hand there are two moles present, who are they?

Bill, Ken, and Mark are, not necessarily in this order, a quarterback, a receiver, and a kicker.  The kicker, who is the shortest of the three, is a bachelor.  Bill, who is Ken’s father-in-law, is taller than the receiver.

Who plays in which position?

A boy and a girl are sitting on the porch.  “I’m a boy,” says the child with black hair.  “I’m a girl,” says the child with red hair.

If at least one of them is lying, who is which?