What is the 5th term of this geometric sequence? 100, 20, 4, 0.8, ...

a. 124.8

b. 0.2

c. 0.16

d. 0.032

First we have to find out the common number of them.

For that purpose, the first number should be divided by next number.

100/20 = 5

20/4 = 5

4/0.8 = 5

we have found that 5 is the common number.

0.8/5 = 0.16

therefore the answer is c