Answer 3

1. Aqua does not belong as it's the only one which is not a tree. Willow does not belong as it's the only one which is not a colour. 

2. Sword does not belong as it's the only one which is not a family pet. Hamster does not belong as it's the only one which is not a type of fish. 

3. Double does not belong as it's the only one which is not a person of royalty. Prince does not belong as it's the only one which is not a bed size.

just_moi