Number Series:
The given sequence is 120, 80, 40, 45, ?, 5. To find the missing number, we need to identify the pattern or rule followed in the given sequence.

Pattern or Rule:
To identify the pattern or rule, we can look at the differences between consecutive terms in the sequence.

- The difference between the first and second terms is 120 - 80 = 40.
- The difference between the second and third terms is 80 - 40 = 40.
- The difference between the third and fourth terms is 40 - 45 = -5.
- The difference between the fourth and fifth terms is 45 - ? = -40.

From the given differences, we can observe that the first three terms follow a pattern of decreasing by 40. However, the fourth term differs by -5 instead of -40. This suggests that there might be a change in the pattern from the fourth term onwards.

Possible Solution:
Based on the pattern observed, we can assume that the fifth term should be 45 - 40 = 5. However, the given fifth term is 5, which indicates that there might be a mistake in the sequence or the pattern is not consistent.

Coding and Decoding:
The given sequence does not seem to follow a specific coding and decoding pattern. Coding and decoding typically involve substitution or transformation of letters or numbers based on a specific rule or algorithm. In this case, there is no evident rule or algorithm that can be applied to the given sequence.

Odd Man Out:
The odd man out refers to a number or element that does not fit with the rest of the sequence or set. In the given sequence, all the numbers seem to follow a specific pattern or rule except for the fourth term, which is 45. The other terms in the sequence are multiples of 40 (120 = 40 * 3, 80 = 40 * 2, 40 = 40 * 1), while 45 does not fit this pattern. Therefore, the odd man out in this sequence is 45.

Conclusion:
In conclusion, the missing number in the sequence cannot be determined with certainty as the given sequence does not follow a consistent pattern or rule. However, based on the observed pattern, the missing number could be 5. Additionally, the odd man out in the sequence is 45, as it does not fit the pattern followed by the other terms.