Question

There are five people in a room you enter with a gun and kill four people now how many people remains in the room ???

Answer 1

Original number of persons in room are 5
After you enter the room number of persons become 6.
Now after killing four people,
No of persons left = 6 - 2 = 4
Thus, the required solution is 4.

Answer 2

Let the no.of people alive be x. People in room =5  U enter the room and kill 4 people = 4  x= 5-4=1 :. x=1