Аnswear the question using a possessive pronoun.
Whose car is this? (Rob's)
Whose bikes are there?(your and a friend's)
Whose cold it this? (Sarah's)
Whose books are there?(Andy's and Tony's)
Whose bag is this? (yours)
Whose car is this? (your two friend's)

It is Rob's. They are yourse and your friend's. It is Sarah's.They are Andy's and Tony's. It is yours. They are mine and my two friend's.