Understanding and applying arithmetic series

Find the sum:  90 + 84 + 78 + ... + 24

• 276
• 627
• 684
• 741

Find the sum of first 20 even numbers.

• 400

• 410

• 420

• 430

Find the sum of the first 20 even numbers.

• 400

• 410

• 420

• 430

Evaluate the related series of the sequence 13, 15, 17, 19, 21, 23.

• 108

• 107

• 106

• 105

What is  $\sum_{k=1}^5\left(5k+2\right)$  equal to?

• 25

• 45

• 65

• 85

Determine a sum of a given finite AR sequence:

S₂₅₀ = 2 + 4 + 6 + …. + 498 + 500

Find the sum: 400 + 394 + 388 + .... - 32

• 400

• 13432

• 432

• 73

 $\sum_{x=3}^9\left(2x+2\right)$  How many terms are in the sequence?

• 6

• 7

• 3

• 2

Find the sum of the arithmetic sequence -8, -5, -2, ..., 7.

• -5

• -3

• -7

• -2

Given the following:  $a_1=−3,\ d=2,\ S_n=21$ , how many terms do the arithmetic sequence have?

• 11

• 9

• 7

• 5