To answer the question, we may directly use the calculator by inputting the expression 3 x (-2)^(n - 1) or manually as follows,
n = 1 ; 3 x (-2)^(1 - 1) = 3
n = 2 ; 3 x (-2)^(2 - 1) = -6
n = 3 ; 3 x (-2)^(3 - 1) = 12
n = 4 ; 3 x (-2)^(4 - 1) = -24
n = 5 ; 3 x (-2)^(5 - 1) = 48
S = 3 - 6 + 12 - 24 + 48 = 33
Thus, the summation is equal to 33 which is the third among the four choices.
