Cars Across the Desert

A military car carrying an important letter must cross a desert. 

There is no petrol station on the desert and the car has space only for petrol that lasts to the middle of the desert.

There are also other cars that can transfer their petrol into one another.

How can the letter be delivered?

This is how letter can be delivered!

Source 

Delivering Letter Across The Desert

What was the task?

We need 4 such cars to deliver the letter across the desert successfully.

Let's divide the entire route into 6 parts. That means the distance that car can travel (half the total path in desert) is divided into 3 parts. To travel each part car requires 1/3rd of it's petrol in the tank.

1. At first 1/6th of total path, all cars are 2/3rd full. Now 2/3rd of the petrol from 1 car can be used to fill 1/3rd of tanks in other 2 cars (1/3 + 1/3 = 2/3). This way, we would have 2 cars full while 1 car 2/3rd full. We are leaving behind the empty car, taking 3 cars forward.

Stage 1

2. At next 1/6th of the distance, 2 full cars will use 1/3rd of their petrol hence would be 2/3rd full. And the car that was 2/3rd at previous stage would be not 1/3rd full. At this stage, the petrol from car that is 1/3rd full can be used to fill tank of 1 car completely. So we are leaving behind one another empty car here & taking fully filled car & 2/3rd filled car for next stage.

Stage 2

3. For next 1/6th of the total distance, the car that was fully filled would have 2/3rd petrol. And the car which was 2/3rd at previous stage would be now 1/3rd filled. The petrol of this car can be used to fill the tank of the first car. Now we have 1 car fully filled while other one is empty. So we can leave behind the empty car & use fully filled car for the rest half of the journey. Remember, a car which tank is full can travel half the total path.

Stage 3

 

Who Works Where?

Alex, Betty, Carol, Dan, Earl, Fay, George and Harry are eight employees of an organization
They work in three departments: Personnel, Administration and Marketing with not more than three of them in any department.

Each of them has a different choice of sports from Football, Cricket, Volleyball, Badminton, Lawn Tennis, Basketball, Hockey and Table Tennis not necessarily in the same order.

1.Dan works in Administration and does not like either Football or Cricket.

2.Fay works in Personnel with only Alex who likes Table Tennis.

3.Earl and Harry do not work in the same department as Dan.

4.Carol likes Hockey and does not work in Marketing.

5.George does not work in Administration and does not like either Cricket or Badminton.

6.One of those who work in Administration likes Football.

7.The one who likes Volleyball works in Personnel.

8.None of those who work in Administration likes either Badminton or Lawn Tennis.

9.Harry does not like Cricket.

 
Who are the employees who work in the Administration Department?

In which Department does Earl work?

Who is the fan of each sports?

Click here for the complete picture. 

Source 

Employees of Each Department

What was the data given? 

Let's make a table where columns represent the sport & row represents the employee.There are 3 tables 1 for each department. To make table shorter we will use the initials only of sports' & employees' names as below.

Table

A - Alex, B - Betty, C - Carol, D - Dan, E - Earl, F - Fay, G - George, H - Harry. 

F - Football, C - Cricket, V - Volleyball, Bd - Badminton, LT - Lawn Tennis, Bs - Basketball,
H - Hockey, TT - Table Tennis  

Now taking clues one by one into consideration.

1. Dan works in Administration and does not like either Football or Cricket.

Table 1

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2. Fay works in Personnel with only Alex who likes Table Tennis.

This indicates that Alex is working in Personnel department & likes Table Tennis. Fay working in same department may like any other sports than Table Tennis. No body other working in this department.

Table 2

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3. Earl and Harry do not work in the same department as Dan.

Hence they must be working in Marketing department!

Table 3

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4. Carol likes Hockey and does not work in Marketing.

That's why his department must be Administration.

Table 4

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5. George does not work in Administration and does not like either Cricket or Badminton.

His department must be Marketing & he might be liking Football or Volleyball or Lawn Tennis or Basketball.

Table 5

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The Seven Rings

You arrive at a hotel and have 3 sets of golden rings. The first set of rings has 4 rings, the second set has 2 rings and the third only has one ring. You cannot take these sets of rings apart, exchange them for a different form of currency, and the hotel clerk has no change. You want to stay at the hotel for 7 nights, and you have to pay one gold ring for each night that you stay. You cannot pay in advance, or all at once at the end of your stay.

 How do you pay for your 7 nights at the hotel?

This is how should you pay! 

Source 

Paying Rings At Hotel

What was the condition? 

You can pay 7 rings in 7 days in following sequence.

Day 1 : 

Give the only ring that is in first set. Paid 1 ring.

Day 2 : 

Take back ring given on Day 1 & give second set of rings having 2 rings. Paid 2 rings

Day 3 :

Give 1 ring back again. Total rings paid = 2 + 1 = 3

Mathematical Coincidence

Messi entered a candy shop and spent half of the money in his pocket. When he came out he found that he had just as many paise as he had rupees when he went in and also half a many rupees as he had paise when he went in. How much money did he have on him when he entered? (1 Rupee = 100 Paise just like 1 Dollar = 100 Cents)

Know the amount that Messy had initially!!

Source