# Arithmetic Series Formula Practice Problems

Solve each problem on paper then click the ANSWER button to check if you got it right.

**Problem 1:** Find the sum of the first [latex]300[/latex] natural or counting numbers.

## Answer

[latex]\color{red}45,150[/latex]

**Problem 2:** What is the sum of the first 100 positive **odd** numbers?

## Answer

[latex]\color{red}10,000[/latex]

**Problem 3:** What is the sum of the first 100 positive **even** numbers?

## Answer

[latex]\color{red}10,100[/latex]

**Problem 4:** Find the sum of the first **64 terms** of the arithmetic series below.

[latex]3 + 9 + 15 + 21 + …[/latex]

## Answer

[latex]\color{red}12,288[/latex]

**Problem 5:** Find the sum of the first **50 terms** of the arithmetic series below.

[latex] – 5 + \left( { – 8} \right) + \left( { – 11} \right) + \left( { – 14} \right) + …[/latex]

## Answer

[latex]\color{red} – 3,925[/latex]

**Problem 6:** Find the partial sum of the arithmetic series below.

[latex]7 + 12 + 17 + 22 + … + 187[/latex]

## Answer

[latex]\color{red}3,589[/latex]

**Problem 7:** Find the partial sum of the arithmetic series below.

[latex] – 8 – 11 – 14 – 17 – … – 113[/latex]

## Answer

[latex]\color{red}-2,178[/latex]

**Problem 8:** The 15th term of the arithmetic sequence is [latex]33[/latex] and the 50th term is [latex]103[/latex]. What is the 79th partial sum of the arithmetic sequence?

## Answer

[latex]\color{red}6,557[/latex]

**Problem 9:** The 7th term of the arithmetic sequence is [latex]-19[/latex] and the 13th term is [latex]35[/latex]. What is the 30th partial sum of the arithmetic sequence?

## Answer

[latex]\color{red}1,725[/latex]

**Problem 10:** The 9th term of an arithmetic sequence is [latex]57[/latex] while its 18th partial sum is [latex]1,080[/latex]. Find the sum of the first 31 terms of the sequence.

## Answer

[latex]\color{red}3,069[/latex]

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