SBI PO type high level floor stay reasoning puzzle solved in a few confident steps 1

Solve SBI PO type high level floor stay reasoning puzzle quickly and systematically

SBO PO type high level floor stay reasoning puzzle solution 1 cover

In this first session on solving SBI PO type high level reasoning puzzles, we will use the power of collapsed column minimal logic table representation together with goal directed strategic execution of logic statements to solve a high level floor stay reasoning puzzle in a series of systematic steps without any confusion.

For detailed concepts on the fundamental technique and strategies in solving this type of logic puzzles you should refer to our tutorial sessions,

How to solve SBI PO level logic puzzles in a few simple steps 1

How to solve SBI PO level logic puzzles in a few simple steps 2

How to solve SBI PO level family relation problems in a few simple steps 3

How to solve SBI PO level floor stay Reasoning Puzzle in a few confident steps 4

How to solve high level circular seating reasoning puzzles for SBI PO in confident steps 5

How to solve high level hard two row seating reasoning puzzles for SBI PO in confident steps 6

Note: Go through the following brief concepts, but before going through the solution of the problem, try to solve the problem in a suitably timed exercise session.


Collapsed column technique adapted to Floor stay Reasoning puzzles

Nature of problem

In a Reasoning Floor stay arrangement problem, a group of people stay in a multi-storied house, usually one person in each floor and no floor vacant, which is a one to one relationship between the set of Persons and the set of Floors. A set of condition statements determine who stays in which floor. This is the simplest form of problem of this type.

A second level of complexity is introduced often by an additional parameter or characteristic of the persons. This may be a set of professions, a set of hobbies or a set of anything personal. Accordingly, the representation of the logic table, the analytical process and the number of condition statements will also increase.

We will solve such a Floor stay Reasoning puzzle of second level difficulty.

Representation of logic table for Reasoning Floor stay problem

Whatever be the complexity level of a Reasoning Floor stay problem, the corresponding collapsed column logic table will have the Floors as the rows, with lowest numbered floor as the bottom row and the highest numbered floor as the top row, other floors in increasing numbers forming the intervening rows sequentially increasing in number from bottom to top. This is an exact replication of the system of floors in a real life multi-storied building. This is the most important characteristic of the logic table representation for this type of problem.

In its simplest form of floor stay problem with only persons to be allotted to floors, only one collapsed column will hold floor assignments of each person. To record intermediate possibilities though we may need to use additional Possibility columns which will be temporarily used till the final allotment.

The upwardly increasing floor numbers is essential for dealing with condition statement like, "Person A stays in a floor just below the floor the person B stays in".

The analysis of the condition statements will be based on the domain knowledge which is common knowledge on floor system of a multi-storied building and so this part is not elaborated further.

As in the problem we are going to solve, each person has an additional characteristic, the logic table will have the same structure with an additional row for each floor. Essentially, there will be one final collapsed column and each floor row a compound row with two cells per column. This is necessary to hold the allotment of a person who stays on a particular floor as well as the additional characteristic of the person, two values for each row column cross-section.

SBI PO type high level Floor stay Reasoning Puzzle : Who stays in which floor?

Problem description

A building has seven floors numbered one to seven, in such a manner that the ground floor is numbered one, the floor above it, numbered two and so on such that the topmost floor is numbered seven. One of the seven professors, namely, A, B, C, D, E, F, and G lives on each floor, but not necessarily in the same order.

Each one of the professors teach a different subject among the seven subjects, Maths, Psychology, History, Astronomy, Physics, Innovation and Genetics but not necessarily in the same order.

Conditional statements

  1. Only one person lives between A and the one teaching Maths.
  2. F lives immediately below the one teaching Innovation.
  3. The one teaching Innovation lives on an even-numbered floor.
  4. Only three people live between the ones teaching Maths and Astronomy.
  5. Only three people live above the floor on which A lives.
  6. E lives immediately above C.
  7. E does not teach Astronomy.
  8. Only two people live between B and the one teaching Genetics.
  9. The one teaching Genetics lives below the floor on which B lives.
  10. The one teaching History does not live immediately above B or immediately below B.
  11. D does not live immediately above or immediately below A.
  12. G does not teach Psychology.

Questions

Question 1. How many people live between the floors of D and the one teaching Innovation?

  1. Three
  2. Two
  3. One
  4. More than 4
  5. Four

Question 2. Who lives on the floor immediately above E?

  1. The one teaching Innovation
  2. The one teaching Psychology
  3. The one teaching Physics
  4. The one teaching Genetics
  5. The one teaching History

Question 3. Which of the following subjects does D teach?

  1. Astronomy
  2. Psychology
  3. Genetics
  4. History
  5. Maths

Question 4. Four of the following are alike in a certain way and so form a group. Which is the one that does not belong to that group?

  1. G
  2. F
  3. D
  4. C
  5. A

Question 5. Which of the following is true with respect to G as per the given information?

  1. The one who lives immediately below G teaches Innovation
  2. G lives on the lowermost floor
  3. G lives on floor numbered 6
  4. G lives immediately below E
  5. G teaches Maths

Note: Try to solve the problem yourself before going through the solution.

Solution to the floor stay reasoning puzzle : Problem analysis and representation

There are three sets of objects, the 7 Floors, the 7 Professors staying on each floor, and 7 subjects they teach.

Let us look at the representation first.

In floor stay problems, the logic table representation is very specific. The floors must represent actual physical floors with floor number increasing from bottom to top. As there are 7 floors there will be then 7 row labels with bottom-most row labelled as 1 which represents the floor numbered 1. The topmost floor will be numbered 7 and it will be represented by the topmost row label 7.

As object sets are three in number with unique one to one relation between members of the three sets, the collapsed column will only be 1. The column header label will be, "Professor-Subject". A cell under the single header column and against a specific numbered row will contain the name of the person staying on this floor number as well as the subject being taught by the person. To accommodate two values against each floor, the rows will be compound rows with two rows for each floor.

The final certain allotments of a Professor-Subject pair of values to the seven floors will be accommodated in a single column and seven double cell rows. But while analyzing the logic statements, not always we will be able to allot values to a final column cell with certainty. Instead, we will be able to form more than one possible allotments of a combination of values to one or more than one row.

Unless you record such intermediate possible combinations, you won't be able to resolve such an uncertainty by a later statement thereby reaching the final goal much faster.

For any efficient solution of this type of problem, forming, recording and later resolution of possible combinations are essential activities. This falls under the general skill category of Pattern Identification and Use. Sudoku game play is rich with this type of pattern identification challenges.

This gives rise to the need of, what we call intermediate possibility recording. The first column will hold the certain and final assignments and depending upon the complexity of the problem, we will add 1 or more than 1 number of additional Possibility columns to record these interim possible staying combinations.

For our problem we will use two such additional Possibility columns which should be enough for solving this problem we feel. In any case, if we need we can increase the number of Possibility columns any time while solving the problem.

Thus, the starting logic table will be as below. We will write the lists of names of Professors and Subjects at the top of the table and will go on striking off the name labels as they are assigned to a floor with certainty.

We will start with the following framework of collapsed column logic table.

SBO PO level difficult floor stay reasoning puzzle solution 1-1

This basically is the logic table representation that we will use for solving this floor problem. As explained earlier, the seven floors are specified by seven row labels. Each row label represents a compound row consisting of two rows. Against each such compound row, two values for Professor-Subject pair will be finally assigned in the single final assignment column when we are able to make such an assignment with certainty.

Otherwise we will record possible assignment combinations in columns, Possibility 1 and Possibility 2.

Strategic selection of logic statements

ForĀ quick systematic solution to any logic puzzle of this type, minimal logic table representation is not enough, it is absolutely necessary also,

To select and execute the logic statements in such a way that at every step the certain assignments to primary object set or potential for such certain assignment is maximized.

In other words, at every step our main objective will be,

To make a certain assignment of a secondary object to a primary object, and if not possible, to create the groundwork for such certain assignments as much as possible for future.

Essentially the selection of the logic statements will not be sequential from beginning to end, but will be determined by suitable strategies that maximize the certainty of assignments to primary object set.

In this way, the suitable logic analysis strategies and the compact column (or row) minimal logic table representation together produce efficient and confident pathway to the final solution.

Let us now solve the problem by analyzing and processing the logic statements.

Solution Step 1

Strategy 1: Certain assignment to a primary object

We will first execute those conditional statements that directly define a certain relation between a secondary object to a primary object, that is, between a person and a specific floor in this case.

In this problem we find no such statement at first. But on closer analysis we find Statement 5: "Only three people live above the floor on which A lives." indirectly says, A can live only on floor number 4. This is an indirect or implicit certain allotment of a person to a floor.


Note: At the start, always look for an explicit certain assignment, if not, search for a statement that implies a certain assignment. In the first step of solving such a problem invariably you should find such a certain allotment. If such a certain allotment is not present at all in the logic statements either explicitly or implicitly, the problem should prove to be unusually complex for attempting in SBI PO or other test environment.


Strategy 2: Link search

After allotting A to floor number 4, we search for a statement that has a reference to A which is already assigned. This is link search technique and proves to be extremely useful.

The Statement 1. "Only one person lives between A and the one teaching Maths." satisfies the criteria and creates two possible allotments of Maths to floor 6 and floor 2. We record these two possibilities in columns Possibility 1 and Possibility 2.

Continuing applying link search technique we look for a statement that refers to subject Maths now. Such a Statement 4. "Only three people live between the ones teaching Maths and Astronomy." enriches Possibility 1 with subject Astronomy in floor 2, and Possibility 2 with subject Astronomy in floor 6. In this action,

Existing possibilities are enriched without increasing number of possibilities.

This is a very important criterion for selecting a statement for processing.

Strategy 3: Analytical certain assignment

At this point we identify a very useful pattern in the cell allotments with respect to the Statement 3. "The one teaching Innovation lives on an even-numbered floor.", which leaves subject Innovation only for floor 4. This is because both the other even number floors 6 and 2 have already been allotted by either of Maths or Astronomy.

Thus it turns out that, A teaches subject Innovation.


Note: This analytically arrived at certain assignment is possible only because the logic table is fairly filled up with certain values. At any stage one should look for such opportunities.


Strategy 2 of link search continued further

Continuing link search technique further, we search for a statement referring to subject Innovation. This results in processing of Statement 2. "F lives immediately below the one teaching Innovation." which allots F to floor 3 with certainty.

After systematic execution of these five statements the logic table looks like,

SBO PO level difficult floor stay reasoning puzzle solution 1-2

Solution Step 2

Strategy 4: Processing a group of statements

At this stage of step 2, we are confronted with a difficulty - which statement to process! There is no further link in any of the remaining statements to any of three values already allotted with certainty. This is where we have to be ready to process either a statement that along with already assigned values produces an assignment without increasing the number of possibilities, or a group of statements that have a common referred element.

We find such a group in Statement 8. "Only two people live between B and the one teaching Genetics." and Statement 9. "The one teaching Genetics lives below the floor on which B lives." with subject Genetics and professor B being the two common referred elements. These two statements together forces B to floor 6 and Genetics to professor F in floor 3, two certain assignments.

Check this step yourself.


Note: More often than not, this technique or strategy to fruitfully process a suitable group of statements together, lies at the heart of success in solving a particularly tricky logic puzzle efficiently.

An important point to remember:

Never go for this more complex strategy without exhausting the possibilities of using the simpler strategies first.

This is because, if you use this technique earlier than justified, the logic table in that case will be sparsely assigned, and consequently instead of creating certainties, uncertainties may be increased uncontrollably.


So, the logic table now looks like,

SBO PO level difficult floor stay reasoning puzzle solution 1-3

Solution Step 3

We continue with the same strategy as in the previous step to identify Statement 6. "E lives immediately above C." and Statement 7. "E does not teach Astronomy.", which together not only forces E to floor 2 and C to floor 1, as E does not teach Astronomy, the second statement also makes the Possibility 1 invalid. This is the crucial state in which we are left with no uncertain possibility.

The Possibility 2 column being the only one left, it becomes a certainty and its values are to be merged with the Final column.

We show the logic table state before merging as below,

SBO PO level difficult floor stay reasoning puzzle solution 1-4

Solution Final Step 4

This is the final step where only three statements are left. We will select Statement 11. "D does not live immediately above or immediately below A.", first as it definitively forces D to the floor 7, the top floor.

With this assignment, the only professor G left to be assigned has the lone unassigned floor 5 and gets it with certainty. This is assignment by exclusion, a frequently used technique in solving large puzzles, such as Sudoku game plays.

The next Statement 10. "The one teaching History does not live immediately above B or immediately below B." again forces subject History to C in the floor 1, the bottom floor and finally the Statement 12. G does not teach Psychology." decides subject Physics for G and Psychology for D. The logic table is now fully assigned and shown below.

SBO PO level difficult floor stay reasoning puzzle solution 1-5

Here the two possibility columns are superfluous and have no more use. We have shown these in the figure for symmetry between all the figures.

Now we are ready to answer the questions and it should take only about a minute's time to answer the five questions.

Answers to the questions

Question 1. How many people live between the floors of D and the one teaching Innovation?

Answer 1. Option 2: Two.

Question 2. Who lives on the floor immediately above E?

Answer 2. Option 4: The one teaching Genetics.

Question 3. Which of the following subjects does D teach?

Answer 3. Option 2: Psychology.

Question 4. Four of the following are alike in a certain way and so form a group. Which is the one that does not belong to that group?

Analysis: As among choices G, F, D, C, A, all the four of G, F, D, C live on odd numbered floors they form a group with only A living on an even numbered floor 4. So A does not belong to this group.

Answer 4. Option 5: A.

Note: You should be able to identify the key pattern of similar characteristic of the four choice values here.

Question 5. Which of the following is true with respect to G as per the given information?

Answer 5. Option 1: The one who lives immediately below G teaches Innovation.

All the other options are false.

Recommendation

Without solving a sufficient number of such logic assignment problems during timed practice sessions one may not gain enough confidence and ability to solve a tricky logic puzzle or logic analysis question in an important competitive test.


Tip

A powerful method of enhancing useful pattern identification and logic analysis skill, Play Sudoku in a controlled manner. But beware, this great learning game, popularly called Rubik's Cube of 21st Century, is addictive.

To learn how to play Sudoku, you may refer to our Sudoku pages starting from the very beginning and proceeding to hard level games.


You may refer to the following reading list on SBI PO level Reasoning puzzles of various types.

Reading list on SBI PO and Other Bank PO level Reasoning puzzles

Tutorials

How to solve SBI PO level logic puzzles in a few simple steps 1

How to solve SBI PO level logic puzzles in a few simple steps 2

How to solve SBI PO level family relation problems in a few simple steps 3

How to solve SBI PO level floor stay Reasoning Puzzle in a few confident steps 4

How to solve high level circular seating reasoning puzzles for SBI PO in confident steps 5

How to solve high level hard two row seating reasoning puzzles for SBI PO in confident steps 6

Solved reasoning puzzles

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SBI PO type high level reasoning puzzle solved in a few confident steps 3

SBI PO type high level circular seating reasoning puzzle solved in confident steps 4

SBI PO type high level hard reasoning puzzle solved in confident steps 5

SBI PO type high level one to many valued group based reasoning puzzle solved in confident steps 6

SBI PO type high level hard two in one circular seating reasoning puzzle solved in confident steps 7

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SBI PO type high level four dimensional reasoning puzzle solved in confident steps 9

SBI PO type hard two row seating reasoning puzzle solved in confident steps 10

Bank PO type two row hybrid reasoning puzzle solved in confident steps 1