'Fifteen' in the Bible

And thou shalt till the land for him, thou, and thy sons, and thy servants; and thou shalt bring in the fruits , that thy master's son may have bread to eat: but Mephibosheth thy master's son shall eat bread alway at my table. Now Ziba had fifteen sons and twenty servants.

And there were a thousand men of Benjamin with him, and Ziba the servant of the house of Saul, and his fifteen sons and his twenty servants with him; and they went through the Jordan in the presence of the king.