The average of first ten prime numbers is:

Options

A. 10.1
B. 10
C. 12.9
D. 13

Answer

To find the average of the first ten prime numbers, we will follow these steps:

### Step 1: Identify the first ten prime numbers.
The first ten prime numbers are:
1. 2
2. 3
3. 5
4. 7
5. 11
6. 13
7. 17
8. 19
9. 23
10. 29

### Step 2: Sum the first ten prime numbers.
Now, we will add these numbers together:
\[ 2 + 3 + 5 + 7 + 11 + 13 + 17 + 19 + 23 + 29 \]

Calculating the sum step by step:
- \(2 + 3 = 5\)
- \(5 + 5 = 10\)
- \(10 + 7 = 17\)
- \(17 + 11 = 28\)
- \(28 + 13 = 41\)
- \(41 + 17 = 58\)
- \(58 + 19 = 77\)
- \(77 + 23 = 100\)
- \(100 + 29 = 129\)

So, the total sum is \(129\).

### Step 3: Divide the sum by the number of terms.
To find the average, we divide the sum by the number of prime numbers (which is 10):
\[ \text{Average} = \frac{\text{Sum of prime numbers}}{\text{Number of prime numbers}} = \frac{129}{10} = 12.9 \]

### Final Answer:
The average of the first ten prime numbers is \(12.9\).

---