we know the given term are in geometric progression.
we know that first term is a which is equal to 8 .
second term is 8 which can be represented as 64.
to find common ratio we have a formula
common ratio =[tex] r=a_{2} /a_{1} =64/8=8. [/tex]
if we do the same for second and third term will get the same 8 .
in geometric progression common ratio is equal between two terms