SSS2 Math Quiz 19.5- The sum of an arithmetic series

 If the last term is known, the sum of the first \( n \) terms of the arithmetic series is given by the formula:

The first term of an arithmetic series is 5, the common difference is 3, and the number of terms is 8. What is the sum of the series?

Find the sum of the first 20 terms of the arithmetic series: \( 2, 6, 10, 14, \dots \).

The sum of the first 10 terms of an arithmetic series is 150, and the first term is 5. What is the common difference?

The sum of the first \( n \) terms of an arithmetic series is 195, the first term is 10, and the common difference is 5. Find the value of \( n \).

If the first term of an arithmetic series is 8 and the sum of the first 5 terms is 70, what is the common difference?

The sum of the first 12 terms of an arithmetic series is 240. If the first term is 15, find the common difference.

What is the sum of the first 25 terms of the arithmetic series: \( 4, 9, 14, 19, \dots \)?

The sum of the first \( n \) terms of an arithmetic series is 136, the first term is 4, and the common difference is 3. Find the value of \( n \).

If the first term of an arithmetic series is 3 and the common difference is 7, what is the sum of the first 6 terms?