Found all 3 in the first less than 30 seconds. Same with puzzle 3 and 4.. On two I missed the hair, I must be getting tired, it is late and I worked out 2 times today pretty hard and I'm doing these without my reading glasses. #5 I missed two of them. Now I know I'm tired and should go to bed.
The elevator on the right is going to the 3rd floor and the man in the back is bald. The elevator on the left is going to the 4th floor and the man in the back has hair.