How many son's does W have ?

Statements : I. X's father has three children.

II. Y is X's brother and son of W.

Read the question & statements (I & II). Decide whether the data provides in the statement are sufficient to answer the question.

If I & II together are not sufficient

Statements : I. X's father has three children.

II. Y is X's brother and son of W.

From the above statements it is clear that W has 3 children but none of the statements clarifies that whether the children son or daughter.

So none of the statement is able to tell that how many son's does W have .