Why did penn want the duke of yorks 3 counties?

Answer: He wanted access to the sea.

Explanation:

William Penn (1644-1718) was the founder of the English North American colony, the Province of Pennsylvania.

As a Quaker leader, Penn was given a permission to found a new colony in America. Penn knew that his colony's location (far away from the Atlantic ocean) would make trade difficult, which is why he asked the Duke of York if he would give him the land by the Delaware River, known as 'the lower counties on the Delaware.'