Question

Which summation formula represents the series below?

Answer 1

we are given

$12-24+48-96$

we can see that

total number of terms is 4

so, n=4

first term is 12

$a_1=12$

$a_2=-24$

now, we can find common ratio

$r=\frac{-24}{12}$

$r=-2$

now, we can find nth term

$a_n=a_1 (r)^{n-1}$

$a_n=12 (-2)^{n-1}$

so,

option-B.........Answer

Answer 2

Answer:

12 - 24 + 48 - 96 = -160

Step-by-step explanation:

12 - 24 = -12

-12 + 48 = 36

36 - 96 = -60