Hi Puzzling Stack Exchange! Here's a quick deduction puzzle I thought of. It's a slight twist on the classic version, but should prove fun (not agonising) to solve. Enjoy!
sound of breaking glass
Those moronic kids. Looking out your window, you can see a boy run away from your house; however, the frost on the glass blurred out any defining features.
You make your way downstairs. The cracking of your legs is almost as loud as the creaking of the dusty, wooden staircase.
As you reach the bottom, you almost drop your walking stick in horror.
The family heirloom: a vase, made from the finest china, and passed down from generation to generation for over five hundred years, lay on the floor, shattered into pieces. Next to it was a stone - the obvious destroyer.
Luckily for you, you live in a very small town. There are seven male kids in your town: Arthur, Benjamin, Connor, Daniel, Eric, Frederick, and Gary. You ask them to each tell you one thing, and to make this riddle more easily solvable, you know for a fact that three of them will definitely give you (and each other) falsified information, whereas the other four will definitely give you (and each other) truthful information.
Arthur: I think that Daniel thinks that Eric will tell the truth.
Benjamin: I know Gary, and I know for a fact that Gary and I will both tell the truth.
Connor: I don't know who threw the stone, but it was either Daniel, Eric, or Frederick.
Daniel: I know both Connor and Eric, and I know for a fact that they will either both lie, or both tell the truth.
Eric: I don't know who threw the stone, but it was either Benjamin, Connor, or Daniel.
Frederick: I think that Gary thinks that Connor thinks that Arthur will lie.
Gary: I know both Arthur and Benjamin, and I know for a fact that one of them is a liar, and one of them will tell the truth.
Hmm. Perhaps it would have been easier if you had asked them questions instead.
Who threw the stone?
Note: Just to make the above information a little clearer so there are no misconceptions, if someone is a liar, they will lie to the other kids as well! For example:
Larry is a liar. Martin is a liar.
If you ask Larry what he thinks of Martin, he will say that Martin is a liar. This is because Martin would tell Larry that he tells the truth, but Larry would lie to you, telling you that Martin is a liar.
However, if Larry says that he knows Martin, he will tell you that he knows for a fact that Martin will tell the truth. This is because he knows Martin is a liar, and will lie to you, telling you that Martin will tell the truth.
Update: Can't believe I didn't include this, but it was a liar that threw the stone. Hopefully that should help clear things up.