Explanation:

- To find the average of the first 10 multiples of 11, first list them: 11, 22, 33, 44, 55, 66, 77, 88, 99, 110.

- Calculate their sum: 11 + 22 + 33 + 44 + 55 + 66 + 77 + 88 + 99 + 110 = 605.

- Divide the sum by the number of multiples, which is 10: 605 ÷ 10 = 60.5.

- Therefore, the average of these numbers is 60.5.

- Option 1: 60.5 - This is the correct answer.

- Option 2: 55.5 - Incorrect. It doesn't match the calculated average.

- Option 3: 55 - Incorrect. It's lower than the correct sum.

- Option 4: 60 - Incorrect. Close, but not the exact average.

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