Question #7a5dd

1 Answer
Sep 14, 2017

63.9375

Explanation:

The formula of the geometric series (sum of n-terms of a pattern):
S_n=(a(1-r^n))/(1-r)Sn=a(1rn)1r
Where n is the number of terms, 10 in your case, and r is the common ratio.

The common ratio can be found by dividing any term from the term before:
r=a_(n+1)/a_nr=an+1an

Let us take any two terms and divide them:
a_2/a_1=16/32=1/2a2a1=1632=12

Now that we have the common ratio(1/2)(12) and the first term (32), we can calculate the sum.
S_10=(32(1-(1/2)^10))/(1-(1/2))S10=32(1(12)10)1(12)

Simplifying:
S_10=(32-32/2^10)/(1/2)S10=323221012

Putting this in the calculator:
S_10=(32-32/2^10)/(1/2)=63.9375S10=323221012=63.9375