Problem Setup
Analyze the given constraints for the circular table arrangement:
- There are 7 people: A, B, C, D, E, F, and G.
- They are seated around a circular table facing the center.
- Constraint 1: Exactly 2 people sit between F and C when counting clockwise from F.
- Constraint 2: Exactly 2 people sit between C and A when counting clockwise from C.
- Constraint 3: Exactly 3 people sit between F and G when counting clockwise from F.
- Constraint 4: E sits immediately to the left of D (meaning E is counter-clockwise to D, or E D in clockwise order).
- The question asks for the number of people between D and F when counting clockwise from D.
Step-by-Step Solution
Step 1: Determine the relative positions of F, C, and A.
- Imagine 7 seats numbered 1 to 7 clockwise. Let F be at seat 1.
- From Constraint 1 (F _ _ C), C is 3 seats clockwise from F. So, C is at seat 1 + 3 = 4.
- From Constraint 2 (C _ _ A), A is 3 seats clockwise from C. So, A is at seat 4 + 3 = 7.
- The arrangement so far (clockwise) is: F(1), Seat 2, Seat 3, C(4), Seat 5, Seat 6, A(7).
Step 2: Determine the position of G.
- From Constraint 3 (F _ _ _ G), G is 4 seats clockwise from F. So, G is at seat 1 + 4 = 5.
- The arrangement is now: F(1), Seat 2, Seat 3, C(4), G(5), Seat 6, A(7).
Step 3: Place D and E using Constraint 4.
- The remaining seats are 2, 3, and 6.
- The remaining people are B, D, and E.
- Constraint 4 states E is immediately left (counter-clockwise) of D. This means in clockwise order, they appear as E D.
- The only adjacent pair of empty seats that fits the E D clockwise pattern is Seat 2 (for E) and Seat 3 (for D).
- Arrangement: F(1), E(2), D(3), C(4), G(5), Seat 6, A(7).
Step 4: Place the remaining person B.
- The only empty seat left is Seat 6. B must be at Seat 6.
- The final clockwise arrangement is: F, E, D, C, G, B, A.
Step 5: Answer the question.
- The question asks for the number of people between D and F, counted clockwise from D.
- D is at Seat 3. F is at Seat 1.
- Counting clockwise from D: The sequence is D -> C(4) -> G(5) -> B(6) -> A(7) -> F(1).
- The people sitting between D and F in this direction are C, G, B, and A.
- There are 4 people between D and F.