N=1/5 I think i had this question before.
Answer:
f(x+1)=(5/6)f(x)on: Five-sixths Superscript f (x)
EXPLANATION:
The defining characteristic of a geometric sequence is that each term is a constant multiple of the previous term, called the common ratio denoted r in the rules for geometric equations.
625/750=750/900=etc=r=5/6
It will cost $16.6 to buy 20 cookies. Hope it help!