Explanation:

- The average score of A, B, and C is 78. This means A + B + C = 3 * 78 = 234.

- The average score of C, D, and E is 52, which means C + D + E = 3 * 52 = 156.

- The average score of E and F is 48, implying E + F = 2 * 48 = 96.

- The average score of E and C is 60, indicating E + C = 2 * 60 = 120.

- To find the average score of A, B, C, D, E, and F, first calculate the total scores of all individuals.

- Summing the equations: (A + B + C) + (C + D + E) + (E + F) = 234 + 156 + 96 = 486.

- Using the equation E + C = 120, we can find the total: Total = 234 + D + F.

- Substituting known values, we calculate: D + F = 486 - (234 + 120) = 132.

- The total for A, B, C, D, E, F is 486. Average = 486 / 6 = 81.

- Given options:

- Option 1: 62

- Option 2: 67

- Option 3: 63

- Option 4: 61