1. Which of the following is an arithmetic sequence?
a. 2, 5, 9, 14, 20
b. 1, 3, 6, 10, 15
c. -5, -2, 1, 4, 7
d. -3, 0, 4, 9, 15
2. Which of the following is a geometric sequence?
a. 1, 2, 3, 4, 5
b. 7, 12, 17, 22, 27
c. 1, 3, 9, 27, 81
d. -4, 0, 4, 8, 12
e. -6, -4, -2, 0, 2