precalculus 12 grade

Question

KAMRYN GOT SOME HELIUM BALOON FROM HER BEST FRIEND RUT ON HER BIRTHDAY.THE BALLONS LOSE ONE -FIFTH ON THE HELIUM EACH DAY. EACH BALLON WAS FILLED TO A VOLUME OF 2500 IN^3

A) WICH FUNCTION REPRESENTS THE VALUME EACH DAY AS GEOMETRIC SEQUENCE:

an= 2500(1/5)^n-1 , an=2500(4/5)^n-1 , an=2500(1/5)^n, an=2500(4/5)^n

b) HOW MUCH HELIUM WILL BE IN THE BALLON ON THE 10 th DAY( ROUUND TO 3 DECIMAL INCHES CUBES)

Answer 1

the 2nd option is basically correct

2500(1-1/5)^(n-1) = 2500(4/5)^(n-1) cubic inches

You need those parentheses though, as

2500(4/5)^n -1 is incorrect

on 10th day n =10

helium volume left =

2500(4.5)^9 =

335.54432... =

335.544 in^3

rounded to 3 decimal places

Answer 2

If it loses 1/5 then 4/5 remain. Take it from there.