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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
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.
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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.
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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.
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Stage 3 |
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
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.
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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.
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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.
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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!
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Table 3 |
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4. Carol likes Hockey and does not work in Marketing.
That's why his department must be Administration.
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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.
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Table 5 |
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