One-third of the students in a room have blue eyes. Two-thirds of them have blond hair. What part of the students in the room has blond hair and blue eyes?

Answer 1

maybe none, if by "them" you mean all the students.
could be that
1/3 have blue eyes and brown hair
2/3 have brown eyes and blond hair

But, if you mean that 2/3 of the blue-eyed students have blond hair, then
1/3 * 2/3 = 2/9

Extra credit: what is the difference between blond and blonde?