Math Problem Statement

What is the sum of the first 5 numbers in this series: 2, 4, 6, 8, 10?

Solution

The given series is: 2, 4, 6, 8, 10.

These are the first 5 terms of an arithmetic sequence where the first term (a1a_1) is 2 and the common difference (dd) is 2.

To find the sum of the first 5 terms, use the formula for the sum of an arithmetic series:

Sn=n2×(a1+an)S_n = \frac{n}{2} \times (a_1 + a_n)

Where:

  • nn is the number of terms
  • a1a_1 is the first term
  • ana_n is the nth term (in this case, the 5th term)

Plugging in the values:

S5=52×(2+10)S_5 = \frac{5}{2} \times (2 + 10)

S5=52×12=5×6=30S_5 = \frac{5}{2} \times 12 = 5 \times 6 = 30

So, the sum of the first 5 numbers in the series is 30.

Would you like to go over the steps in more detail or have any other questions?

Here are 5 related questions you might be interested in:

  1. What is the sum of the first 10 terms of this series?
  2. How do you find the common difference in an arithmetic sequence?
  3. What is the formula for the sum of an arithmetic series with more than 5 terms?
  4. How do you find the nth term in an arithmetic sequence?
  5. Can the sum of a series be calculated using a different method?

Tip: When working with arithmetic series, always identify the first term and the common difference before applying any formulas.

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Math Problem Analysis

Mathematical Concepts

Arithmetic Sequences
Sum of Series

Formulas

Sum of an Arithmetic Series

Theorems

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Suitable Grade Level

Grades 7-9