Here are the sentences with the correct forms of the verbs:
1 Have Lucy and Mary got cameras?
No, they haven't.
2 Has Bill got a school bag?
Yes, he has. His school bag is big.
3 Kate and Mary have got pencils.
4 Has Laura got a pink pencil case?
Yes, she has. But her pencil case isn't pink, it is blue.
5 Bill and Lucy's books are interesting.