How many persons are designated between U and the one who is immediately junior to T? Study the following information carefully and answer the questions given below:

Nine persons - P, Q, R, S, T, U, V, W and X are working in the company at different designations such as MD, CEO, CFO, CRO, COO, GM, DM, HR and TL but not necessarily in the same order. The designations are given in decreasing order, such that MD is the senior-most designation and TL is the junior-most designation.

X is four persons junior to Q who is senior to CRO. The number of persons senior to Q is one less than the number of persons junior to S. Only three persons are designated between S and T. P is two persons junior to T. The number of persons designated between P and U is one less than the number of persons designated between U and V who is senior to X. W is senior to R who is not TL.

To find the number of persons designated between U and the one who is immediately junior to T, we can analyze the clues step-by-step and reconstruct the hierarchical designations of all nine individuals.

The designations are given in decreasing order of seniority as follows:
1. MD (Senior-most)
2. CEO
3. CFO
4. CRO
5. COO
6. GM
7. DM
8. HR
9. TL (Junior-most)

Step 1: Determine the positions of Q, X, and S
- "X is four persons junior to Q." This means:
$Rank(X)\; -\; Rank(Q)\; =\; 4$
- "Q is senior to CRO (Rank 4)." This means the rank of Q must be 1, 2, or 3.
- "The number of persons senior to Q is one less than the number of persons junior to S." Let's write this as:
$(Rank(Q)\; -\; 1)\; =\; (9\; -\; Rank(S))\; -\; 1$
Simplifying, we get:
$Rank(Q)\; +\; Rank(S)\; =\; 9$

Let's analyze the possible cases for Q:
- Case 1: If Q is at rank 1, then X is at rank 5, and S is at rank 8.
- Case 2: If Q is at rank 2, then X is at rank 6, and S is at rank 7.
- Case 3: If Q is at rank 3, then X is at rank 7, and S is at rank 6.

Step 2: Determine the positions of T and P
- "Only three persons are designated between S and T."
- "P is two persons junior to T." This means:
$Rank(P)\; =\; Rank(T)\; +\; 2$

Let's test our cases:
- In Case 1 (S = 8): T must be at rank 4 (since only three people are between 8 and 4). Thus, P must be at rank 6. This is consistent.
- In Case 2 (S = 7): T must be at rank 3. Thus, P must be at rank 5. This is consistent.
- In Case 3 (S = 6): T must be at rank 2. Thus, P must be at rank 4. This is consistent.

Step 3: Analyze the positions of U and V
- "The number of persons designated between P and U is one less than the number of persons designated between U and V."
- "V is senior to X" ().

Let's apply these to Case 2 (where Q = 2, S = 7, T = 3, P = 5, X = 6):
The remaining empty ranks are 1, 4, 8, and 9.
Since V is senior to X (Rank 6), V must occupy Rank 1 or Rank 4.
If we place V at Rank 4 and U at Rank 9 (TL):
- The number of persons between P (Rank 5) and U (Rank 9) is 3 (Ranks 6, 7, and 8).
- The number of persons between U (Rank 9) and V (Rank 4) is 4 (Ranks 5, 6, 7, and 8).
Since 3 is exactly one less than 4, this arrangement works perfectly.

Step 4: Place W and R
The remaining empty ranks are 1 and 8.
- "W is senior to R who is not TL."
Therefore, W must be at Rank 1 (MD) and R must be at Rank 8 (HR). This satisfies the condition that R is not TL (since U is at Rank 9).

Final Designation Table:
1. MD: W
2. CEO: Q
3. CFO: T
4. CRO: V
5. COO: P
6. GM: X
7. DM: S
8. HR: R
9. TL: U

Answering the Question:
- The person immediately junior to T (CFO, Rank 3) is V (CRO, Rank 4).
- U is TL (Rank 9).
- The persons designated between U (Rank 9) and V (Rank 4) are P (Rank 5), X (Rank 6), S (Rank 7), and R (Rank 8).
- Therefore, there are exactly four persons designated between them.