The game is played over 10 rounds. In each round, the child holding the Buck must pass it directly to a child sitting in one of the following positions:
• Immediately to the left;
• Immediate to the right;
• Second to the left; or
• Second to the right.
The game starts with Bina passing the Buck and ends with Chirag receiving the Buck. The table below provides some information about the pass types and the child receiving the Buck. Some information is missing and labelled as '?'.
| Round | Pass Type | Received by |
|---|---|---|
| 1 | Immediately to the left | Aarav |
| 2 | Second to the right | ? |
| 3 | Immediately to the right | Diya |
| 4 | ? | ? |
| 5 | ? | Aarav |
| 6 | Second to the left | ? |
| 7 | Immediately to the left | Gaurav |
| 8 | Immediately to the left | ? |
| 9 | ? | Farhan |
| 10 | ? | Chirag |
D
Step-by-Step Solution
Key idea: This is a circular passing movement question with modular arithmetic and constraint propagation. We assign numerical positions to the circle and trace the buck's path to find the exact seating arrangement, then check which person's reception count is invariant.
Step 1: Set up coordinates. Let the 7 positions be 0 to 6 in clockwise order. Since they face inside, Left = +1 (clockwise) and Right = -1 (counter-clockwise). 2L = +2, 2R = -2.
Step 2: Trace the buck from Bina. Let Bina be at position 0.
- R1: 1L from 0 position 1. Receiver is Aarav. So Aarav = 1.
- R2: 2R from 1 1 - 2 = -1 6.
- R3: 1R from 6 6 - 1 = 5. Receiver is Diya. So Diya = 5.
- R6: Aarav (1) passes 2L 1 + 2 = 3.
- R7: 1L from 3 3 + 1 = 4. Receiver is Gaurav. So Gaurav = 4.
- R8: 1L from 4 4 + 1 = 5. Receiver is Diya.
Step 3: Determine Farhan and Chirag.
- R8 receiver is Diya (5). R9 passes to Farhan. Valid targets from 5 are 6, 4, 0, 3. Since 4 is Gaurav and 0 is Bina, Farhan must be 6 or 3.
- If Farhan = 6: R10 passes to Chirag. Valid targets from 6 are 0, 5, 1, 4. None of these is Chirag (who must be 2 or 3). Contradiction.
- Thus, Farhan = 3.
- R10 passes to Chirag. Valid targets from 3 are 4, 2, 5, 1. The only unassigned position is 2. So Chirag = 2.
Step 4: Eshan is the last unassigned position: 6.
Step 5: Count receptions and check invariance.
- Fixed receptions: Aarav (R1, R5), Eshan (R2), Diya (R3, R8), Farhan (R6, R9), Gaurav (R7), Chirag (R10).
- R4 receiver is from Diya (5). Targets: 6, 4, 0, 3.
- However, R5 receiver is Aarav (1). The pass from R4 to R5 must reach 1. The positions that can reach 1 are 0, 2, 6, 3.
- Intersecting Diya's targets {6, 4, 0, 3} with valid passers to 1 {0, 2, 6, 3} eliminates 4 (Gaurav).
- So R4 receiver is Eshan, Bina, or Farhan. Gaurav cannot receive the buck in R4.
- Therefore, Gaurav's total reception count is exactly 1. All others have uncertain counts.
Answer: Gaurav (Option D).