About Question enthuware.ocpjp.v8.2.1518 :

[md4422]

the correct answer is any combination of
interests.hashCode(),
name.hashCode(), and
age

right?

interests.hashCode() + name.hashCode() is marked wrong

[admin]

The equals method of the given class uses age (along with name). Therefore, interests.hashCode() + name.hashCode() cannot be correct for the hashCode method because it doesn't use age.
You need to make sure that if equals method return true for two objects then their hashcodes must also be same. interests.hashCode() + name.hashCode() doesn't ensure that.

[md4422]

The equals method of the given class uses age (along with name). Therefore, interests.hashCode() + name.hashCode() cannot be correct for the hashCode method because it doesn't use age.
You need to make sure that if equals method return true for two objects then their hashcodes must also be same. interests.hashCode() + name.hashCode() doesn't ensure that.

you're absolutely correct. It even said it there. the "trick" is that two objects with different interests can still be .equal()

sorry for wasting your time with my idiocy. my brain went into power save mode there