A man in a red shirt is standing next to a woman in a blue dress. They are both holding hands and smiling at each other. A group of 14 men are standing up stairs with a pair of men on each stair with identical shirts on except for one. If a man is standing on a stair, then he is wearing a shirt. If a man is not standing on a stair, then he is not wearing a shirt. Does it logically follow that There is only one person present? Picasso's collection includes masterworks by fellow artists. Can we conclude that Da Vinci's collection includes masterworks by fellow artists?
yes
no
no