The average of 12 numbers is given as 60. This means that the sum of all 12 numbers is:

$\text{Sum of 12 numbers} = \text{Average} \times \text{Number of terms} = 60 \times 12 = 720$

If the first number is 60, we can subtract this from the total sum to find the sum of the remaining 11 numbers:

$\text{Sum of remaining 11 numbers} = 720 - 60 = 660$

Thus, the sum of the remaining 11 numbers is 660.

If you'd like to find the average of the remaining 11 numbers, you can divide this sum by 11:

$\text{Average of remaining 11 numbers} = \frac{660}{11} = 60$

So, the remaining 11 numbers have an average of 60.

Would you like more details or explanations? Here are some related questions to expand your understanding:

1. What happens to the average if one of the remaining numbers is changed?
2. How would the solution change if the first number was different?
3. Can we determine each of the remaining 11 numbers individually?
4. What if we only knew the sum and not the average of the 12 numbers?
5. How does removing a number from a set affect the overall average?

Tip: When you know the average and the total number of terms, you can always find the sum by multiplying the two values.