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Solution to: Thoughtless Thief

There are five statements in which nothing is said about the possible offender:

A1. In high school, I was in the same class as suspect C.
A2. Suspect B has no driving license.
A3. The thief didn't know that it was the car of the chief of police.
B3. I never sat behind the wheel of a car.
C1. I never met suspect A until today.

The statements A1 and C1 seem to be contradictory, but that is not the case! Although at most one of these statements can be true, they can also be both false! For example, suspects A and C might only know each other from primary school.

About the statements A2 and B3, not much can be said (although it seems unlikely that statement A2 would be false and at the same time statement B3 would be true).

In addition, it follows from the introduction that statement A3 is true.

On the basis of an assumption about which suspect is the offender, we can count how many of the remaining statements are true:

Statement:	A is the offender:	B is the offender:	C is the offender:	D is the offender:	None of the suspects is the offender:
B1	false	false	true	false	false
B2	false	true	true	true	true
C2	true	false	true	true	true
C3	false	false	false	true	false
D1	true	true	false	true	true
D2	true	true	true	false	true
D3	true	false	false	false	false
Total:	4 true, 3 false	3 true, 4 false	4 true, 3 false	4 true, 3 false	4 true, 3 false

Combined with the fact that statement A3 is true, this gives:

	A is the offender:	B is the offender:	C is the offender:	D is the offender:	None of the suspects is the offender:
Total:	5 true, 3 false	4 true, 4 false	5 true, 3 false	5 true, 3 false	5 true, 3 false

Because it was given that exactly four statements were true, the statements A1, A2, B3, and C1 must be false, and suspect B must be the offender.

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