Abby, Brenda, Carol, Diane and Emily are all of different ages. Two are liars and three are knights (knights always tell the truth; liars always lie).
Brenda claimed to be younger than Emily.
Carol claimed to be younger than Abby.
Carol claimed to be younger than Brenda.
Carol claimed to be younger than Diane.
Carol claimed to be younger than Emily.
Diane claimed to be younger than Brenda.
Diane claimed to be younger than Carol.
Diane claimed to be younger than Emily.
Emily claimed to be younger than Abby.
Emily claimed to be younger than Diane.
There were two other, similar, statements made, besides the ones metioned above, and in fact those were the only other statements like that that could be made.
That might be a little ambiguous, but resolving this ambiguity is part of the fun, and you can do it.
Who were the two liars and what was the order of their ages?
You can even fill in the two unheard remarks:
_______ claimed to be younger than _______
_______ claimed to be younger than _______
There are eight ways in which all ten of the given statements could be made, allowing that two of the speakers are "liars." There are twenty possible statements to match the syntax given (x claims to be younger than y). The task is then to explore the other ten for each of those eight cases, to find a set for which only two could be said (remembering that the two liars would continue to lie when they spoke). This reduces the eight cases to one:
Carol < Emily < Brenda < Diane < Abby
The Liars are Brenda and Diane.
The two other statements which "could be made" are
Brenda claimed to be younger than Carol (which is factually false, but Brenda is a liar).
Emily claimed to be younger than Diane (which is true, and Carol is a knight).
The only think ambiguous (or perhaps just misleading) is to think that one does not need to determine that there are exactly two additional statements which could be made from the ten relations not initially given. Mutatis mutandis, Charlie!
No ambiguity at all
