Arithmetic and Geometric Sequences Graded Review Quiz

Identify the arithmetic sequence.

• 10, 20, 30, 40, 50,....

• 10, 20, 30, 20, 10,.....

• 10, 30, 90, 270, 810,....

• 10, 10, 20, 20, 30, 30

Which is not a way to find d in an arithmetic sequence?

• any term subtracted by the term before it

• term - previous term

• 2nd term - 1st term

• 5th term - 4th term

• 1st term - 2nd term

Choose all of the geometric sequences

• 1, 2, 4, 8, 16,....

• 400, 200, 100, 50, 25,....

• 100, 400, 700, 1000,.....

• 5, -15, 45, -135, ......

Tags

CCSS.HSF.BF.A.2

CCSS.HSF.LE.A.2

Choose all of the ways that work to find the multiplicative ratio (r) in a geometric sequence:

•  $\left(1st\ term\right)\ \left(2nd\ term\right)$  
  

•  $\frac{any\ \ \ term}{previous\ \ \ term}$  

•  $\frac{\left(10th\ \ \ term\right)}{\left(9th\ \ \ term\right)}$  

•  $\frac{\left(1st\ \ \ term\right)}{\left(2nd\ \ \ term\right)}$  

Identify the first term

 $a_1$  and difference in the sequence: 150, 105, 60, 15,....

•  $a_1$  = -45,  d = 150
  

•  $a_1$  = 150, d= -45

•  $a_1$  =150, d = 45

•  $a_1$  = 15, d = 45

Identify the first term and r in the sequence: 90, 60, 40, 80/3, ...

• r = 2/3

• r = 1.5

• r = .6

• r = 3/2

Which is a correct way to write the formula for the arithmetic sequence: 50, 57, 64, 71, ....

• $a_n=50\ +\ 7\left(n-1\right)$

• $a_n=50\ -7\left(n-1\right)$

• $a_n=7\ +\ 50\left(n-1\right)$

• $a_n=57\ +\ 7n$

Which is a formula for the geometric sequence:

• $a_n=a_1\left(r\right)^{n-1}$

• $a_n\ =\ r\left(a_1\right)^{n-1}$

• $a_n=\ \left(\left(a_1\right)\left(r\right)\right)^{n-1}$

• $a_n=a_1+r\left(n-1\right)$

Which is the formula for the geometric sequence: 500, 200, 80, 32,....

• $a_1=500\left(0.4\right)^{^{n-1}}$

• $a_1=500\left(2.5\right)^{^{n-1}}$

• $a_1=\left(0.4\right)\left(500\right)^{^{n-1}}$

• $a_1=32\left(2.5\right)^{^{n-1}}$

What is the 51st term of the arithmetic sequence: 12, 21, 30,....

• 462

• 473

• 48

• 453