'Fifteen' in the Bible

You and your sons and your servants shall cultivate the land for him, and you shall bring in the produce, so that your master’s grandson may have food to eat; but Mephibosheth, your master’s grandson, shall always eat at my table.” Now Ziba had fifteen sons and twenty servants.

and a thousand men [from the tribe] of Benjamin with him. And Ziba, the servant of the house of Saul, and his fifteen sons and twenty servants with him, rushed down to the Jordan before the king.