An old challenge from an old Portuguese book I have:
Abdul Al-Kwaritz-Amuhmahd was a Arabic sultan who became very famous by the size of his harem and the number of children he had fathered. More so because many of his children were twins, triplets or quadruplets.
One of the legends about this, tells that all the children of the sultan were twins, except 39 of them.
On a remote oasis, in the middle of the desert, another saying states that all of them were triplets, except 39.
The sultan descendants defend, however, that all were quadruplets except 39.
Ajihad Ahmed-Humahli Hijá, an investigator, says that all the three states about the children of the sultan are true. If he is right, hom many children did the sultan have fathered?
For the purists: the sultan had, at least one "normal" child (not a twin, nor a triplet, nor a quadruplet) and, at least, one pair of twins.