Shirley has a credit card that uses the previous balance method. The opening
balance of one of her 30-day billing cycles was $2830, but that was her
balance for only the first 2 days of the billing cycle because she then paid off
her entire balance and didn't make any new purchases. If her credit cards
APR is 19%, which of these expressions could be used to calculate the
amount Shirley was charged in interest for the billing cycle?

(a) common ratio in the given sequence is, 3

(b) push ups will do kendall do on the 20th week

step-by-step explanation:

geometric sequence is a sequence of numbers that follows a pattern were the next term is found by multiplying by a constant called the common ratio(r)

(a)

given the sequence: 6 , 18 , 54 , 162 ,

this sequence is geometric sequence where each term is 3 times the previous term.

therefore,

common ratio(r) = 3.

(b)

a formula for nth term of geometric sequence is given by;

,   where r is the common ratio between the successive terms and is the first term,

to find how many push ups will kendall do on the 20th week.

here. n = 20th term.

in the given sequence first term

then;

simplify:

therefore, push ups will do kendall do on the 20th week