12.3 Exercise 5

Determine if each sequence is geometric. If so indicate the common ratio.

ⓐ $7 , 21 , 63 , 189 , 567 , 1,701 , \ldots$

ⓑ $64 , 16 , 4 , 1 , \frac{1}{4} , \frac{1}{16} , \ldots$

ⓒ $2 , 4 , 12 , 48 , 240 , 1,440 , \ldots$