What is the sum of the first five odd numbers?

What is the sum of the first five odd numbers?

• A. 20
• B. 25
• C. 30
• D. 15

Answer: (B)

To determine the sum of the first five odd numbers, we start by identifying what those numbers are: the first five odd numbers are 1, 3, 5, 7, and 9. Now, we can calculate their sum step by step: 1. Adding the first two: \(1 + 3 = 4\) 2. Adding the next odd number: \(4 + 5 = 9\) 3. Adding the next one: \(9 + 7 = 16\) 4. Finally, adding the last odd number: \(16 + 9 = 25\) So, the total sum of the first five odd numbers is 25. This value is confirmed by the formula for the sum of the first \(n\) odd numbers, which states that the sum is equal to \(n^2\). For the first five odd numbers, \(n = 5\): \[ \text{Sum} = 5^2 = 25 \] Using either method, we arrive at the same conclusion that the sum is indeed 25. This aligns with the selected answer.

To determine the sum of the first five odd numbers, we start by identifying what those numbers are: the first five odd numbers are 1, 3, 5, 7, and 9.

Now, we can calculate their sum step by step:

1. Adding the first two:

(1 + 3 = 4)

2. Adding the next odd number:

(4 + 5 = 9)

3. Adding the next one:

(9 + 7 = 16)

4. Finally, adding the last odd number:

(16 + 9 = 25)

So, the total sum of the first five odd numbers is 25.

This value is confirmed by the formula for the sum of the first (n) odd numbers, which states that the sum is equal to (n^2). For the first five odd numbers, (n = 5):

[

\text{Sum} = 5^2 = 25

]

Using either method, we arrive at the same conclusion that the sum is indeed 25. This aligns with the selected answer.