The average of first 20 multiples of 12 is :
A. 124
B. 120
C. 126
D. 130

Options

A. A
B. B
C. C
D. D

Answer

To find the average of the first 20 multiples of 12, we can follow these steps:

### Step 1: Identify the first and the 20th multiples of 12.
- The first multiple of 12 is:
\[ 12 \times 1 = 12 \]
- The 20th multiple of 12 is:
\[ 12 \times 20 = 240 \]

### Step 2: Calculate the sum of the first and the 20th multiples.
- Now, we will add the first and the 20th multiples:
\[ 12 + 240 = 252 \]

### Step 3: Calculate the average.
- The average of the first 20 multiples can be found using the formula for the average of two numbers:
\[ \text{Average} = \frac{\text{Sum of first and last multiple}}{\text{Number of multiples}} \]
- Here, the number of multiples is 20. Therefore:
\[ \text{Average} = \frac{252}{2} = 126 \]

### Conclusion
- The average of the first 20 multiples of 12 is **126**.

### Answer
- The correct option is **C. 126**.