Who is not alive?
SOLUTION
Person-1
Explanation:
Person-3: Some will say the answer to be person-3 as his body is floating in the water. But the question is do dead bodies float in water?. The answer is yes, but it takes at least 2 to 3 days for a dead body to float. In the starting 1 to 2 days, a dead body sink under the water, thereafter it starts floating. Thus, person-3 is not dead.
Person-2: There is vibration in the water. This makes us sure that person-2 is not dead.
Person-1: If you see closely, he is having a book in his hand and it is in the water. Also, he seems to be in a subconscious state.
So, the answer to this puzzle is Person-1.