### #1

One day, when the wind is blowing from the west, lightning strikes the west end of the island and sets fire to the forest. The fire is very violent, burning everything in its path, and without intervention the fire will burn the whole island, killing the man in the process.

There are cliffs around the island, so he cannot jump off.

How can the Alexander survive the fire? (There are no buckets or any other means to put out the fire)

### #2

Two old friends, Jack and Bill, meet after a long time.

Three kids

Jack: Hey, how are you, man?

Bill: Not bad, got married and I have three kids now.

Jack: That’s awesome. How old are they?

Bill: The product of their ages is 72 and the sum of their ages is the same as your birth date.

Jack: Cool..But I still don’t know.

Bill: My eldest kid just started taking piano lessons.

Jack: Oh, now I get it.

How old are Bill’s kids?

### #3

The below is a number puzzle. It should be read left to right, top to bottom.

1

1 1

2 1

1 2 1 1

1 1 1 2 2 1

? ? ? ? ? ?

? ? ? ? ? ? ? ?

Question 1: What is the next two rows of numbers?

Question 2: How was this reached.

### #4

Outside a room there are three light switches. One of switch is connected to a light bulb inside the room.

Each of the three switches can be either ‘ON’ or ‘OFF’.

You are allowed to set each switch the way you want it and then enter the room(note: you can enter the room only once)

Your task is to then determine which switch controls the bulb ??

### #5

Two batsman each on 94 runs. Seven runs needed to win in last 3 balls. Both make 100*. How?

### #6

You are given a set of scales and 12 marbles. The scales are of the old balance variety. That is, a small dish hangs from each end of a rod that is balanced in the middle. The device enables you to conclude either that the contents of the dishes weigh the same or that the dish that falls lower has heavier contents than the other.

The 12 marbles appear to be identical. In fact, 11 of them are identical, and one is of a different weight. Your task is to identify the unusual marble and discard it. You are allowed to use the scales three times if you wish, but no more.

Note that the unusual marble may be heavier or lighter than the others. You are asked to both identify it and determine whether it is heavy or light.

### #7

Create a number using only the digits 4,4,3,3,2,2,1 and 1. So i can only be eight digits. You have to make sure the ones are separated by one digit, the twos are separated by two digits the threes are separated with three digits and the fours are separated by four digits

### #8

Using eight eights and addition only, can you make 1000?

### #9

Distances from you to certain cities are written below.

BERLIN 200 miles

PARIS 300 miles

ROME 400 milesAMSTERDAM 300 miles

CARDIFF ??? miles

How far should it be to Cardiff ?

### #10

You find yourself in a strange place guarded by two guards.One of the guard always say truth while other always lies.You don’t know the identity of the two.You can ask only one question to go out from there. What should you ask?

#### Answers are provided below –

**#1**

Alexander picks up a piece of wood and lights it from the fire on the west end of the island.

He then quickly carries it near the east end of he island and starts a new fire. The wind will cause that fire to burn out the eastern end and he can then shelter in the burnt area.

Alexander survives the fire, but dies of starvation, with all the food in the forest burnt….

**#2**

3,3,8

Lets break it down. The product of their ages is 72. So what are the possible choices?

2, 2, 18 sum(2, 2, 18) = 22

2, 4, 9 sum(2, 4, 9) = 15

2, 6, 6 sum(2, 6, 6) = 14

2, 3, 12 sum(2, 3, 12) = 17

3, 4, 6 sum(3, 4, 6) = 13

3, 3, 8 sum(3, 3, 8 ) = 14

1, 8, 9 sum(1,8,9) = 18

1, 3, 24 sum(1, 3, 24) = 28

1, 4, 18 sum(1, 4, 18) = 23

1, 2, 36 sum(1, 2, 36) = 39

1, 6, 12 sum(1, 6, 12) = 19

The sum of their ages is the same as your birth date. That could be anything from 1 to 31 but the fact that Jack was unable to find out the ages, it means there are two or more combinations with the same sum. From the choices above, only two of them are possible now.

2, 6, 6 sum(2, 6, 6) = 14

3, 3, 8 sum(3, 3, 8 ) = 14

Since the eldest kid is taking piano lessons, we can eliminate combination 1 since there are two eldest ones. The answer is 3, 3 and 8.

**#3**

3 1 2 2 1 1

1 3 1 1 2 2 2 1

Line 1 is ‘Two ones’ (2 1)

Line 2 then becomes ‘One two, and one one’ (1 2 1 1)

Line 3 therefore is ‘One one, one two and two ones’ (1 1 1 2 2 1)

Line 4 is ‘Three ones, two twos and one one’ (3 1 2 2 1 1)

Line 5 is ‘One three, one one, two twos and two ones’ (1 3 1 1 2 2 1 1)

### #4

Set the first switches on for abt 10min, and then switch on the second switch and then enter the room.

Three cases are possible

1.Bulb is on => second switch is the ans

2.Bulb is off and on touching bulb , you will find bulb to be warm

=>1st switch is the ans.

3.Bulb is off and on touching second bulb , you will find bulb to be normal(not warm)

=>3rd bulb is the ans.

### #5

Batsman hit six and gone retired hurt while the new batsman come to play and get runout for his wicket and the other batsman hit six and made both century and team win..

### #6

So that the following plan can be followed, let us number the coins from 1 to 12. For the first weighing let us put on the left pan coins 1,2,3,4 and on the right pan coins 5,6,7,8.

There are two possibilities. Either they balance, or they don’t. If they balance, then the different coin is in the group 9,10,11,12. So for our second one possibility is to weigh 9,10,11 against 1,2,3

(1) They balance, in which case you know 12 is the different coin, and you just weigh it against any other to determine whether it is heavy or light.

(2) 9,10,11 is heavy. In this case, you know that the different coin is 9, 10, or 11, and that that coin is heavy. Simply weigh 9 against 10; if they balance, 11 is the heavy coin. If not, the heavier one is the heavy coin.

(3) 9,10,11 is light. Proceed as in the step above, but the coin you’re looking for is the light one.

That was the easy part.

What if the first weighing 1,2,3,4 vs 5,6,7,8 does not balance? Then any one of these coins could be the different coin. Now, in order to proceed, we must keep track of which side is heavy for each of the following weighings.

Suppose that 5,6,7,8 is the heavy side. We now weigh 1,5,6 against 2,7,8. If they balance, then the different coin is either 3 or 4. Weigh 4 against 9, a known good coin. If they balance then the different coin is 3, otherwise it is 4. The direction of the tilts can tell us whwther the offending coin is heavier or lighter.

Now, if 1,5,6 vs 2,7,8 does not balance, and 2,7,8 is the heavy side, then either 7 or 8 is a different, heavy coin, or 1 is a different, light coin.

For the third weighing, weigh 7 against 8. Whichever side is heavy is the different coin. If they balance, then 1 is the different coin. Should the weighing of 1,5, 6 vs 2,7,8 show 1,5,6 to be the heavy side, then either 5 or 6 is a different heavy coin or 2 is a light different coin. Weigh 5 against 6. The heavier one is the different coin. If they balance, then 2 is a different light coin.

### #7

41312432

### #8

888 + 88 + 8 + 8 + 8 = 1000

### #9

100 miles. Each vowel is worth 300 and each consonant is worth -100. These are totalled in each city name to give the distance.

### #10

If you ask the guard who always tells the truth, he would tell you the other guard would point you to the door of death. If you ask the guard who always lies, he would tell you the opposite door of the truth-telling guard and point you to the door of death. In either case, both guards will point to the door of death so you should choose the other one.

**Source: **

http://www.briddles.com

**Jai Hind, Vande Mataram****Team CA Study**