The third term of a geometric sequence is -10, and the fourth term is -5. Find the first term and the fifth term. 

a. a1 = 80 and a5 = 2

b. a1 = -40 and a5 = 5/2

c. a1 = 40 and a5 = 5/2

d. a1 = -40 and a5 = -5/2


Find the common ratio of the given geometric sequence: -1, 3, -9, 18, ... 

a. -1/3

b. -3

c. 1/3

d. 3


The third term of a geometric sequence is -10, and the fourth term is -5. Find the common ratio. 

a. -1/2

b. -2

c. 1/2

d. 2​