Find the sum of first 5 multiples of 4

Options

A. 40
B. 50
C. 60
D. 70

Answer

To find the sum of the first 5 multiples of 4, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the first 5 multiples of 4**:
- The first multiple of 4 is \(4 \times 1 = 4\)
- The second multiple of 4 is \(4 \times 2 = 8\)
- The third multiple of 4 is \(4 \times 3 = 12\)
- The fourth multiple of 4 is \(4 \times 4 = 16\)
- The fifth multiple of 4 is \(4 \times 5 = 20\)

So, the first 5 multiples of 4 are: **4, 8, 12, 16, 20**.

2. **Sum the multiples**:
- We can add these multiples together:
\[ 4 + 8 + 12 + 16 + 20 \]

3. **Calculate the sum**:
- Adding them step by step:
\[ 4 + 8 = 12 \]
\[ 12 + 12 = 24 \]
\[ 24 + 16 = 40 \]
\[ 40 + 20 = 60 \]

Therefore, the sum of the first 5 multiples of 4 is **60**.

4. **Verification using the formula**:
- We can also use the formula for the sum of an arithmetic series:
\[ S_n = \frac{n}{2} \times (2a + (n-1)d) \]
where:
- \(n = 5\) (the number of terms)
- \(a = 4\) (the first term)
- \(d = 4\) (the common difference)

Plugging in the values:
\[ S_5 = \frac{5}{2} \times (2 \times 4 + (5-1) \times 4) \]
\[ = \frac{5}{2} \times (8 + 16) \]
\[ = \frac{5}{2} \times 24 \]
\[ = \frac{120}{2} = 60 \]

This confirms that the sum is indeed **60**.

### Final Answer:
The sum of the first 5 multiples of 4 is **60**.