Crystal Heshmat sends us this tale of her Native American ancestors...
The first squaw, who sits on a tiger skin, says that her son is short and muscular, weighing in at 40 kilograms.
The second squaw, who sits on a lion skin, says that her son is lean and tall, weighing in at 30 kg.
The third squaw, who sits on a hippopotamus skin, says that _she_ weighs 70 kg.
So, the squaw on the hippopotamus equals the sons of the squaws on the other two hydes!