(hint: the required number is any one of the four numbers: 8, 7, 2, 4 )
Come back tomorrow for the correct answer to this teaser.
Answer for yesterday's Brain Teaser
There are three bulbs in a room with no windows. Their switches are outside the room and you don’t know which switch is connected to which bulb. You can turn the switches on and off as many times as you like but can enter the room only once. How will you determine which switch is connected to which bulb?
Turn the first switch on and keep it in that position for five minutes. Then turn it off and the second switch on. Now enter the room. The bulb, which is lighted, is connected to the second switch. Now touch the other two bulbs. The warmer bulb is connected to the first switch, while the other bulb is connected to the third switch.