Sequences and Series

Arithmetic Sequence

100

Find the 20^th term of the sequence:

5, 8, 11, 14, ... a₂₀

62

200

What is the formula for finding the nth term of an arithmetic sequence?

a_n=a₁+(n-1)d

300

Find the common difference of the sequence:

6, 4, 2, 0, -2, -4 , ...

-2

400

Find the missing element in this arithmetic sequence:
a₁=-22, a_n=14, n=10, d=?

d=4

500

Find d given that a₁=10 and a₂₀=466

d=24

Geometric Sequence

100

0.5, 0.25, 0.125, ____

0.0625

200

50, 25, 12.5, ____

6.25

300

1/3, 2/3, 4/3, ____

8/3

400

What is the formula for finding the n^th term of a geometric sequence?

a_n=a₁*r^(n-1)

500

Find r given that a₁=1/2 and a₃=8

r=4

Arithmetic/Geometric Series

100

Find the sum of the sequence 1, 2, 3, 4, ..., 112, 113, 114

6555

200

a₁=9 and a₆=24, find S₆=?

S₆=99

300

Find S₁₀ of the sequence: 4, 8, 12, 16, ...

1 398 100

400

Find the sum of the first 8th terms of the sequence: {1,2,4,8…a₈}

255

500

Find the sum of the first 13th terms of the sequence: {3,5,7,9…a₁₃}

195

Sigma Notation

100

The symbol called sigma means it is looking for the ___

sum/summation

200

Find the sum of the first 75 counting numbers.

2850

300

⁸_i=1∑5=?

40

400

²⁰_i=12∑5=?

45

500

¹⁰_i=1∑3i=?

165