#81 - Making The Century Puzzle

Use the digits from 1 up to 9 and make 100.

Follow the rules.
=> Each digit should be used only once.
=> You can only use addition.
=> For making a number, two single digits can be combined (example, 4 and 2 can be combined to form 42 or 24)
=> A fraction can also be made by combining the two single digits (example, 4 and 2 can be combined to form 4/2 or 2/4)

Question: how can we do this ?

There are various solutions that one can come up with. Following are some of them.
1 + 2 + 5 + 4/6 + 7/3 + 89 =100
12 + 9 + 75 + 6/3 + 8/4 =100
2 + 95 +1/6 + 4/8 + 7/3 =100
24 + 57 + 8 + 6/3 + 9/1 =100
36 + 51 + 9 + 4/8 + 7/2 =100
5 + 91 + 3/2 + 6/8 + 7/4 =100

#82 - Chance Of Surviving Puzzle

Once upon a time there were three rivals who got together in a dark wood on an open spot for composing a quarrel by using guns. It was a kind of duel but there were three people in it and therefore it is a truel. There were A, B and C. there was some rules to be followed in the game. The rules of the games were:
-They have to draw the lots in order to find who will fire first and who will be second and who will be third.
- The next rule is that, they will start firing on each other unless there is a last person alive.
- Each person will decide on his own about which person he will fire on.
-it is quite clear that A hits and kills in all the shots and it is 100%. Whereas 80% of the shots are hit by B and C hits in 50% of the shots he tries to fire in. the three persons have their own strategy for firing. Nobody is killed by the stray bullet.

Question: who will have the highest chances for surviving in the truel and how much is the chance?

the person C will have the highest chances of survival.
Person A hits = 1
Person A misses = 0
Person B hits = 4/5
Person B misses = 1/5
Person C hits = 1/2
Person C misses = 1/2

#83 - Find Number Problem

Find out a number which is less than 100 and is more than one fifth of its actual value when the digits are reversed.

The number is 45
1/5 of 45 = 9
9+45 is 54.

#84 - James Bond Archer Of The Blind

James Bond is caught up in a mysterious scenario where the evil villain has him blindfolded. He somehow breaks through the handcuffs but is unable to get the blindfold off. Upon searching, he comes across a bow and 3 arrows. He can hear the villain speak, and thus tries to take a shot at him. He launches the first arrow, it misses the villain. He then launches the second arrow and it misses by a greater margin.

What is the probability that this third shot our james bond takes will be worse than the second shot?

2/3. How? Well, since he has 3 arrows, each shot has 1/3rd chance of being the best shot. So the chance that the third shot is not the best shot is 1 minus 1/3rd, thus 2/3rd.

#85 - Number Of Races Puzzle

In order to complete the racing competition, the London racetrack has to submit its top and the most famous three horses to win the competition. Due to a electrical storm, all the records are cleared and no one knows which horse holds the record. They all look identical and it becomes even more difficult to differentiate the horses. There are 25 horses in the London racetrack. But there can be only five horses at a time on the track. What will the least number of races that can be conducted to find out the three fastest horses?

The numbers of races are 7.

#86 - Create Function Puzzle

There are two variables x and y. Jimmy is required to construct a function f(a,b) which returns the maximum one in {a,b}.
You can only use +,-,ยท, / & abs() (to take the absolute value). NO if () is allowed in to jimmy.

Solve this one, math freaks.

{a+b+abs(a-b)}/2
Also, {a+b-abs(a-b)}/2 is the smaller one in {a,b}

#87 - The Great Chocoberry Problem

Rohan, a 7 year old boy, was really fond of the chocolates called "Chocoberries". He asked his Mrs. Mother to give him some money to buy his favorite chocolates. His Mrs. Mother gave him Rs 45. He went to the shopkeeper and asked, "how much is one chocoberry for?". The shopkeeper said, Rs 3 for one chocolate. Also, if you give me the wrappers of three chocoberries, I will give you one for for the exchange.
In total, how many chocoberries could Rohan eat?

22.

He can buy 15 chocolates at first from the 45 bucks that he has. Then further, he can exchange the 15 rappers to get 5 more. Then he can return 3 rappers of the 5 to get one more chocolate, and in the end use the wrapper from this one alongwith the 2 left with him to get one more. 15+5+1+1= 22.

#88 - Chances Of Survival Probability Puzzle

You are trapped into a death trap by the famous jigsaw killer. As usual, a screen flashes in front of you and explains you the trap game.

There are 100 pearls kept in a bowl in front of you and an empty bowl. Among the 100 pearls, 50 are white and 50 are black. You can divide them as you like into the two bowls. Once you are done, you will pull a lever, which will turn the room pitch black. The bowls will move and shuffle around. In the dark, you have to pick up one pearl from any bowl. Once you do that, the room will flood with lights again. If the peral you have in your hand is white, you will be allowed to live, but if the pearl you picked is black, the room will be filled with poisonous gas and you will die.

How will divide the pearls to increase your chances of survival?

For best probability of living, you must place one white pearl in a bowl and all the rest into another bowl.

This gives you a 1/2 probability of choosing a bowl which has just a white pearl. If you choose that, you will live.
If you choose another, you will still have an almost 1/2 probability of picking up a white pearl. (49 white pearls and 50 black pearls).

#89 - Who Is Taller Puzzle

500 women soldiers are arranged in an array of ten rows and fifty columns in accordance with their respective heights. Now, the tallest woman from each row is asked to move out in the front. From them, the shortest one is labelled as Alpha. They are then asked to resume their original position.

Now, the shortest woman in each column is asked to come out in front. The tallest among them is labelled as Beta.

Can you find out if Alpha will be taller or Beta?

Alpha and Beta are the same woman.

Let us begin by making the assumption that the numbers represent the height of the women.

Now, the tallest among 1, 2, 3, 4 etc. will be 50 or Alpha.
The shortest among 50, 100, ... , 500 will be 50 or Beta.

Therefore, they both are the same woman.

#90 - Bottles Count Logic Maths Puzzle

A shopkeeper allows people to buy a bottle of cold drink in exchange of five empty bottled. A guy had a party at home and he managed to spend 77 cold drink bottles in the party. Now he has 77 empty bottles with him.

How many bottles do you think he can buy in exchange of those 77 empty bottles ?

He can purchase 19 new bottles in return.

He will get 15 bottles after returning 75 empty bottles and will be left 2 empty bottles.
Now, the 15 bottles when empty will get him 3 more bottles.
The three empty bottles will get him another bottle. Remember he had 2 empty bottles as well.