From New Scientist #1117, 24th August 1978 [link]
I had been away from the Island of Imperfection for some time and I was amused — and rather distressed — on a recent visit to find that there was now another tribe there.
But I had better explain. In the old carefree days, which I knew so well, there had been three tribes on the island. The Pukkas, who always told the truth, the Wotta-Woppas, who never told the truth, and the Shilla-Shallas, who made statements which were alternately true and false or false and true. I cannot pretend to know how it happened but now there is another tribe who call themselves the Jokers. I am afraid that all I can tell you about them is that in making three statements their truth-telling rules are any rules that are different from those of the other three tribes. Just to be different! That seems to be all they are interested in, and I find it hard to restrain myself from making some acid comments about the modern generation. They don’t seem to be much interested in fun or laughter but in achievement. And it is no doubt because of this that the main currency of the island is called a Success, and it made up of 100 Hopes.
Four men, A, B, C and D (one from each tribe), make statements as follows:
A: (1) B makes more true statements than D does.
A: (2) My income is 7 Successes and 50 Hopes per week more or less than D‘s income.
A: (3) C is a Wotta-Woppa.
B: (1) A‘s income is 2 Successes and 50 Hopes per week more or less than mine.
B: (2) D‘s second statement is true.
B: (3) C‘s income is 8 Successes and 50 Hopes per week.
C: (1) D is a Joker.
C: (2) My income is 10 Successes per week.
C: (3) B is a Pukka.
D: (1) B is a Joker.
D: (2) My income is 1 Success per week more or less than C‘s income.
D: (3) C is not a Joker.
It was rather interesting to notice that the more truthful a man the less was his income. All their incomes were a multiple of 50 Hopes.
Find the tribes to which A, B, C and D belong and their weekly incomes.