As per the given information,
Q is the eldest person in the group. Only four people were born after N.
| Month | Date | Person |
| March (31) | 18th | Q |
| 26th | |
| May (31) | 18th | |
| 26th | N |
| September (30) | 18th | |
| 26th | |
| October (31) | 18th | |
| 26th | |
Only one person was born between N and P. P was born after R, who was born in the month which has 30 days.
So, R was born on 18th September and P was born on 26th September.
| Month | Date | Person |
| March (31) | 18th | Q |
| 26th | |
| May (31) | 18th | |
| 26th | N |
| September (30) | 18th | R |
| 26th | P |
| October (31) | 18th | |
| 26th | |
P was born before T, who was not born on the 18th.
M and Q were not born in the same month. Four people were born between M and U.
Thus, S was born on 18th May.
| Month | Date | Person |
| March (31) | 18th | Q |
| 26th | U |
| May (31) | 18th | S |
| 26th | N |
| September (30) | 18th | R |
| 26th | P |
| October (31) | 18th | M |
| 26th | T |
Hence, this is the final arrangement.
As per the above arrangement, the first element was born immediately before the second element.
Only T was born immediately after M.
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