Find the sum of the exponential series (96 + 24 + 6 +…)
-
A.
144 -
B.
128 -
C.
72 -
D.
64
Correct Answer: Option B
Explanation
(S_{infty} = frac{a}{1 – r}) (for an exponential series)
(r = frac{24}{96} = frac{6}{24} = frac{1}{4})
(S_{infty} = frac{96}{1 – frac{1}{4}} = frac{96}{frac{3}{4}})
= (frac{96 times 4}{3} = 128)