Eight north-facing restaurants named P, Q, R, S, T, U, V and W are located in a straight line. S is second to the left of T. W is third to the left of P. T is between P and V. S is third to the left of V. W is to the immediate right of U. R is third to the right of P. Who is sitting fourth to the right of S?

The correct answer is R.

We are given 8 restaurants (P, Q, R, S, T, U, V, W) in a straight line at positions 1 through 8 (left to right). Let's decode each clue systematically to fix their positions.

Step 1 — Extract key relationships from the clues:

Clue 1: S is second to the left of T  →  T = S + 2
Clue 4: S is third to the left of V  →  V = S + 3
Clue 3: T is between P and V  →  P ... T ... V (so P < T < V)
Clue 2: W is third to the left of P  →  W = P − 3
Clue 5: W is to the immediate right of U  →  U = W − 1
Clue 6: R is third to the right of P  →  R = P + 3

Step 2 — Notice a sub-chain from Clues 1 and 4:

From Clue 1 and Clue 4 together:
V = S + 3 and T = S + 2, so V = T + 1
This means T is immediately to the left of V, consistent with Clue 3 (T is between P and V, with P to the left of T).

Step 3 — Try S = 4 (testing valid positions):

If S = 4:
→ T = 4 + 2 = 6
→ V = 4 + 3 = 7

Now, P must satisfy P < T = 6 and W = P − 3 ≥ 1 (valid position). Also P ≠ 4, 6, 7.

Try P = 5:
→ W = 5 − 3 = 2
→ R = 5 + 3 = 8
→ U = W − 1 = 2 − 1 = 1

The only remaining restaurant is Q, which occupies position 3.

Step 4 — Final arrangement:

Position:  1     2     3     4     5     6     7     8
Restaurant: U    W    Q    S    P    T    V    R

Step 5 — Verify all clues:

✅ S(4) is second to the left of T(6): 6 − 4 = 2 ✓
✅ W(2) is third to the left of P(5): 5 − 2 = 3 ✓
✅ T(6) is between P(5) and V(7): 5 < 6 < 7 ✓
✅ S(4) is third to the left of V(7): 7 − 4 = 3 ✓
✅ W(2) is to the immediate right of U(1): 2 − 1 = 1 ✓
✅ R(8) is third to the right of P(5): 8 − 5 = 3 ✓

Step 6 — Answer the question:

Who is sitting fourth to the right of S?
S is at position 4.
Fourth to the right of S = position 4 + 4 = position 8.
Position 8 is occupied by R.

✅ The answer is R.