A, B, C, D, L, M, N and O live on eight different floors of the same building. The lowermost floor in the building is numbered 1, the floor above it, number 2 and so on till the topmost floor is numbered 8.
L lives on the fourth floor. Sum of floor numbers of L and C is more than 10. The sum of floor numbers of D and O is 8. O does not live on an odd numbered floor. M lives on an odd numbered floor. The sum of floor numbers of M and D is more than 12. More than three people live between M and N. The sum of floor numbers of N and A is more than 5.
Which of the following is NOT TRUE based on the given information?
A, B, C, D, L, M, N and O live on eight different floors of the same building. The lowermost floor in the building is numbered 1, the floor above it, number 2 and so on till the topmost floor is numbered 8.
L lives on the fourth floor. Sum of floor numbers of L and C is more than 10. The sum of floor numbers of D and O is 8. O does not live on an odd numbered floor. M lives on an odd numbered floor. The sum of floor numbers of M and D is more than 12. More than three people live between M and N. The sum of floor numbers of N and A is more than 5.
Which of the following is NOT TRUE based on the given information?
Solution
✅ Correct Option: 4
Step 1: Analyze Fixed Information & Basic Constraints
- L is on floor 4.
- O is on an even floor ().
- M is on an odd floor ().
Step 2: Determine positions of D, O, and M
- Constraint: Sum of floors of .
- Since O is even () and L is already on 4:
- If , then (Impossible).
- If , then .
- If , then .
- Constraint: Sum of floors of .
- If , then (Impossible).
- Therefore, D must be 6 and O must be 2.
- With , . Since M is odd, M is on floor 7.
Step 3: Determine positions of C and N
- Constraint: Sum of floors of .
- , so .
- Floors are 7 and 8. Since M is on 7, C is on floor 8.
- Constraint: More than 3 people live between M and N.
- M is on 7. The gap must be at least 4 floors ().
- This forces N to be below floor 3. Floor 2 is O, so N is on floor 1.
Step 4: Determine positions of A and B
- Constraint: Sum of floors of .
- , so .
- Available floors are 3 and 5. Since A must be , A is on floor 5.
- Remaining: The only empty spot is floor 3, so B is on floor 3.
Final Arrangement Table
| Floor | Person |
|---|---|
| 8 | C |
| 7 | M |
| 6 | D |
| 5 | A |
| 4 | L |
| 3 | B |
| 2 | O |
| 1 | N |
Verifying the Options
- A) A lives on a floor immediately above L: True ( is above ).
- B) Only four people live between M and O: True (Floors 6, 5, 4, 3 are between 7 and 2).
- C) C lives on the topmost floor: True (Floor 8).
- D) B lives on floor number 5: FALSE. (B lives on floor 3; A lives on floor 5).
Correct Answer: Option D