Read the following information, and answer the questions given below.
P, Q, R and S live together in a house.
I. P lives with his (or her) parents.
Il. Q lives with at least 3 persons younger than him (or her).
Ill. S lives with his mother, and is older than at least 2 persons living with him.
IV. R lives with his (or her) son and is not older than S.