Ten persons Q, R, S, T, U, V, W, X, Y and Z live in a building that consists of five floors. The bottommost floor is numbered as 1, the floor above it as 2, and so on. Each floor has two flats - Flat 1 and Flat 2. Flat 1 is to the west of Flat 2 on each floor.
They were born in consecutive years starting from 1992 to 2001, but not necessarily in the same order. No two persons were born in the same year.
Their present age is considered as of the year 2024.
| Years | Present age |
| 1992 | 32 years |
| 1993 | 31 years |
| 1994 | 30 years |
| 1995 | 29 years |
| 1996 | 28 years |
| 1997 | 27 years |
| 1998 | 26 years |
| 1999 | 25 years |
| 2000 | 24 years |
| 2001 | 23 years |
R lives on an even-numbered floor with Q.
| Case 1 | | Case 2 | | Case 3 | | Case 4 | |
| Floor 5 | | | | | | | | |
| Floor 4 | R | Q | Q | R | | | | |
| Floor 3 | | | | | | | | |
| Floor 2 | | | | | R | Q | Q | R |
| Floor 1 | | | | | | | | |
| Flat 1 | Flat 2 | Flat 1 | Flat 2 | Flat 1 | Flat 2 | Flat 1 | Flat 2 |
Z lives to the west of Y, who was born in 1994.
S lives immediate below Y in the same flat.
R and S live in the different flats. Thus, case 2 and case 4 are invalid.
| Case 1 | | Case 1a | | Case 3 | | Case 3a | |
| Floor 5 | | | | | Z | Y (30) | | |
| Floor 4 | R | Q | R | Q | | S | Z | Y (30) |
| Floor 3 | Z | Y (30) | | | | | | S |
| Floor 2 | | S | Z | Y (30) | R | Q | R | Q |
| Floor 1 | | | | S | | | | |
| Flat 1 | Flat 2 | Flat 1 | Flat 2 | Flat 1 | Flat 2 | Flat 1 | Flat 2 |
X lives on one of the floors between R and Z. Thus, case 1 is invalid.
Neither U nor X lives in the same flat as Z. Thus, case 3a is invalid.
| Case 1a | | Case 3 | |
| Floor 5 | | U | Z | Y (30) |
| Floor 4 | R | Q | | S |
| Floor 3 | | X | | X |
| Floor 2 | Z | Y (30) | R | Q |
| Floor 1 | | S | | U |
| Flat 1 | Flat 2 | Flat 1 | Flat 2 |
T, who is 31 years old, lives on floor 1.
The person, who lives in flat 2 on floor 3, was born in 1997.
So, the age of X is 27 years.
| Case 1a | | Case 3 | |
| Floor 5 | | U | Z | Y (30) |
| Floor 4 | R | Q | | S |
| Floor 3 | | X (27) | | X (27) |
| Floor 2 | Z | Y (30) | R | Q |
| Floor 1 | T (31) | S | T (31) | U |
| Flat 1 | Flat 2 | Flat 1 | Flat 2 |
All persons living above the floor of X are younger than X. Thus, case 3 is invalid.
So, 26 year, 25 year, 24 year and 23 year old persons live above X.
Only V is younger than R. It means the age of V is 23 years and the age of R is 24 years.
Therefore, V and R live above X.
| Case 1a | |
| Floor 5 | V (23) | U |
| Floor 4 | R (24) | Q |
| Floor 3 | | X (27) |
| Floor 2 | Z | Y (30) |
| Floor 1 | T (31) | S |
| Flat 1 | Flat 2 |
Persons living on floor 5 were born in odd-numbered years.
So, U was born in 1995. Thus, the age of U is 25 years.
| Case 1a | |
| Floor 5 | V (23) | U (25) |
| Floor 4 | R (24) | Q |
| Floor 3 | | X (27) |
| Floor 2 | Z | Y (30) |
| Floor 1 | T (31) | S |
| Flat 1 | Flat 2 |
Therefore, Q was born in 1998. The age of Q is 26 years.
The age of the person who lives with X is 29 years.
| Case 1a | |
| Floor 5 | V (23) | U (25) |
| Floor 4 | R (24) | Q (26) |
| Floor 3 | W (29) | X (27) |
| Floor 2 | Z | Y (30) |
| Floor 1 | T (31) | S |
| Flat 1 | Flat 2 |
Z is younger than S.
Therefore, the final arrangement is:
| Floor 5 | V (23) | U (25) |
| Floor 4 | R (24) | Q (26) |
| Floor 3 | W (29) | X (27) |
| Floor 2 | Z (28) | Y (30) |
| Floor 1 | T (31) | S (32) |
| Flat 1 | Flat 2 |
Z and Y live on floor 2. Their ages are 28 years and 30 years.
So, 28+30 = 58 years.
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