Exploring Sums of Sequences

What is the sum of the first 10 terms of the arithmetic series 2, 5, 8, ...?

• 155

• 160

• 150

• 145

Calculate the sum of the first 15 terms of the arithmetic series 3, 7, 11, ...

• 465

• 400

• 500

• 350

Find the sum of the first 20 terms of the arithmetic series 5, 10, 15, ...

• 2000

• 1050

• 500

• 1500

What is the sum of the first n terms of the arithmetic series 4, 9, 14, ...?

• (n/2) * (5n + 3)

• (n/2) * (3n + 1)

• (n/2) * (6n + 4)

• (n/2) * (4n + 2)

Determine the sum of the first 12 terms of the arithmetic series 1, 4, 7, ...

• 150

• 180

• 240

• 210

Calculate the sum of the first 8 terms of the geometric series 3, 6, 12, ...

• 1024

• 765

• 512

• 150

What is the sum of the first 5 terms of the geometric series 2, 6, 18, ...?

• 120

• 48

• 72

• 242

Find the sum of the first 10 terms of the geometric series 5, 15, 45, ...

• 500

• 300

• 120

• 147620

What is the formula for the sum of the first n terms of a geometric series?

• S_n = a(1 + r^n) / (1 + r) for r ≠ -1

• S_n = a + ar + ar^2 + ... + ar^(n-1)

• S_n = a(1 - r^n) / (1 - r) for r ≠ 1

• S_n = a(r^n - 1) / (r - 1) for r ≠ 1

Calculate the sum of the first 6 terms of the geometric series 1, 2, 4, ...

• 32

• 54

• 48

• 63