Direction: Study the following information carefully to answer the given questions.
Eight persons – A, B, C, D, W, X, Y and Z –are living in a four-storey building such that ground floor is numbered as 1, the floor immediately above floor 1 is numbered as 2 and so on. Each of the floors has two flats in it as flat P and flat Q. Flat Q is to the east of flat P. Flat P of floor 2 is immediately above the flat P of floor 1 and immediately below the flat P of floor 3 and so on. In the same way, flat Q of floor 2 is immediately above the flat Q of floor 1 and immediately below the flat Q of floor 3 and so on.
D lives immediately above the flat in which A lives in the same flat but not in flat Q. There are two floors between the floor on which A and Z live. There is only one floor between the floors on which Z and B live. Y who lives on an even numbered floor lives above the floor on which C lives. C lives below the floor on which X lives. C and X live in the same flat but not with Z.
If W and B interchange their position, then who among the following lives immediately below B?
- AOption (a)
C
- BOption (b)
A
- COption (c)
D
- DOption (d)
X
- EOption (e)
Y
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Correct answer
D
Why this answer is correct
- D lives immediately above the flat in which A lives in the same flat but not in flat Q.
- There is two floors between the floor on which A and Z live.
From this we get the following possibilities.
| Cases | Case 1 | Case 2 | ||
|---|---|---|---|---|
| Floor/Flat | Flat P | Flat Q | Flat P | Flat Q |
| 4th | Z | Z | ||
| 3rd | ||||
| 2nd | D | D | ||
| 1st | A | A |
- There is only one floor between the floors on which Z and B live.
This implies B lives in flat Q on floor 2 in both the cases.
| Cases | Case 1 | Case 2 | ||
|---|---|---|---|---|
| Floor/Flat | Flat P | Flat Q | Flat P | Flat Q |
| 4th | Z | Z | ||
| 3rd | ||||
| 2nd | D | B | D | B |
| 1st | A | A |
- Y who lives on an even numbered floor lives above the floor on which C lives.
- C lives below the floor on which X lives.
From this we can say that Y lives in flat Q and flat P in case 1 and in case 2, respectively. Thus, C lives in flat Q on floor 1 in both the cases. X lives in either flat P or flat Q but lives on floor 3.
| Cases | Case 1 | Case 2 | ||
|---|---|---|---|---|
| Floor/Flat | Flat P | Flat Q | Flat P | Flat Q |
| 4th | Z | Y | Y | Z |
| 3rd | ||||
| 2nd | D | B | D | B |
| 1st | A | C | A | C |
- C and X live in the same flat but not with Z.
From this case 2 is eliminated as we cannot determine the flat in which X lives. Hence, in case 1 X lives in flat Q on floor 3. W lives in flat P on floor 3. From this we get the final arrangement as follows.
| Cases | Case 1 | |
|---|---|---|
| Floor/Flat | Flat P | Flat Q |
| 4th | Z | Y |
| 3rd | W | X |
| 2nd | D | B |
| 1st | A | C |
AFTER INTERCHANGING:
| Cases | Case 1 | |
|---|---|---|
| Floor/Flat | Flat P | Flat Q |
| 4th | Z | Y |
| 3rd | B | X |
| 2nd | D | W |
| 1st | A | C |
If W and B interchange their position, then D lives immediately below B.
Hence, D is the correct option.