Light Bulb Puzzle

Question:
A light bulb is hanging in the first floor of the room. There are three switches in the ground floor room. One of these switches belongs to that light bulb. The light bulb is not lit and the switches are in off state. There is only one chance to visit the room. How can it be determined which of these switch is connected to the light bulb.
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Solution:
First turn ON the first switch and leave it for few minutes. Then turn OFF the first switch and ON the second switch. Now enter the first floor room. If the light bulb is lit, the second switch must be connected to it. If it is not lit, it might the first or the third switch. Now touch the light bulb, it is hot it will be the connected to the first switch. Nor if it is cold, then it should be the third one.

Find The Sum of Second Column 

Answer:

You don't have to find the value of every symbol. The rows add up to 80, and this will be the sum of every symbol in the grid. 23 + 18 + 24 + 15 = 80.

Therefore the columns must also add to 80, making the missing column 14. 24 + 14 + 17 + 25 = 80.

@ = 7, & = 4, $ = 8, # = 3, £ = 5.

The word

Each of the following sets of letters can be made into a real word by adding three letters to the beginning, and the same three letters in the same order to the end.

For example, ANGLEM can have ENT added at the start and the end to become ENT + ANGLEM + ENT = ENTANGLEMENT.

ERTAINM
ISCOVE
ROW
IOXID
ROCOS

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Answer:

ENT + ERTAINM + ENT = ENTERTAINMENT

RED + ISCOVE  + RED = REDISCOVERED

ING + ROW     + ING = INGROWING

ANT + IOXID   + ANT = ANTIOXIDANT

MIC + ROCOS   + MIC = MICROCOSMIC 

Apples and Friends

You have a basket containing ten apples. You have ten friends, who each desire an apple. You give each of your friends one apple.

After a few minutes each of your friends has one apple each, yet there is an apple remaining in the basket.

How?

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.(before you see the answer write your own answer in comments.)
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answer: 
You give an apple each to your first nine friends, and a basket with an apple to your tenth friend.

Each friend has an apple, and one of them has it in a basket.