Time Calculation For Lighting Up The Candles

What is the exact situation?

From a moment from first candle is lit, 30 seconds later there would be total 2 candles lit. In next 30 seconds, each of these 2 candle holders will find 1 candle to lit. So there are now 4 candles lit after 60 seconds. In next 30 seconds, these 4 candles would lit another 4 candles making total 8 candles lit. 

In short, for every 30 seconds, the number of candles lit are doubled. So after 7 sets of 30 seconds, 2^7 = 128 candles would be lit. At 8th set of 30 seconds, 256 candles can be lit. But we have only 200 candles. Still 72 of 128 candles would lit another 72 in 8th set of 30 seconds. 

To conclude, 8 X 30 = 240 seconds = 4 minutes required to lit all 200 candles. 

Strange Creatures on Island

There are people and strange monkeys on this island, and you can not tell who is who (Edit: until you understand what they said - see below). They speak either only the truth or only lies.

Who are the following two guys?

A: B is a lying monkey. I am human.

B: A is telling the truth.

Know who are they! 

 

Identifying the Strange Creature

What was the situation?

 Let's first have statements by 2 creatures - 

A: B is a lying monkey. I am human.

B: A is telling the truth.

If we assume B is telling the truth then A is also telling the truth. But A in statement says B is lying which contradicts our assumption. 

Hence, B must be lying. If B is lying then statement of B suggest that A is also must be lying. That mean 'B is lying monkey' part of statement made by A is too lie. Since we have deduced already B is lying, the lying statement of A suggests that B is not monkey. Hence B is the lying man!

Other lie spoken by A is that it is human. Hence A must be a lying monkey! 

 

Game Of Death - Josephus Problem

There are 100 people standing in a circle in an order 1 to 100. No. 1 has a sword. He kills the next person (i.e. No. 2) and gives the sword to the next (i.e. No. 3). All people do the same until only 1 survives. Which number survives at the last?

Find who survived? 

Source 
 

The Man Surviving in Game Of Death

What was the problem? 

First let's make it very simple by who are surviving after each round.

Round 1 : 1,3,5,7,9,11,13,15..........87,89,91,93,97,99

Round 2 : 1,5,9,13,17.........89,93,97 

Round 3 : 1,9,17,25,33,41,49,57,65,73,81,89,97

Round 4 : 9,25,41,57,73,89

Round 5 : 9,41,73

Round 6 : 9, 73

At round 5, 9 kills 41 & passes sword to 73. So 73 kills 9 & survives.

Round 7 : 73

Now let's analyze  how this happens & trick to get answer at the quickest.

Just for a moment let's assume there were 16 standing in circle.

Now after each round survived people are,

Round 1 : 1,3,5,7,9,11,13,15

Round 2 : 1,5,9,13

Round 3 : 1,9

Round 4 : 1

After round 2, when 9 kills 13 & passes sword to 1.

And in round 4, 1 kills 9. So 1 forms pair with other in every round.

Now imagine there were 17 people in circle. 

Being Alive After Lift Crash Landing? - Puzzle

A lift is on the ground floor. There are four people in the lift including me.When the lift reaches first floor, one person gets in and three people get out.The lift goes up to the second floor, 2 people get out 6 people get in.It then goes up to the next floor up, no-one gets out but 12 people get in. Halfway up to the next floor up the lift cable snaps, it crashes to the floor.

Everyone else dies in the lift. How did I survive?

  
This is how did I! 

Escape from Crash Landed Lift

This was the incident. 

Read carefully once again, in journey from 1st to 2nd floor there are only 2 

people in the lift. At 2nd floor, 2 people get out that means it includes me   

as well. This is how I survived.