There are three people and they are blindfolded. Now, the are given one cap each, two red caps and one black cap, which they wear, unware what color it is. However, they are told that either they have a black cap or a red cap and they can see two other's cap once the blindfold is removed. Also, they are told that once the blindfold is removed, and if they see any red cap, they will have raise their hand. Now they open their eyes. One can't see what one is wearing, but can see two other's cap. One of the people their would be able to tell "I am wearing red cap!" logically. How?