Question 78
Let $a_{1}, \frac{1}{5}, a_{3}, \frac{16}{125}, \ldots$ be a geometric sequence with all terms positive. What is the sum $a_{1}+a_{3}+a_{5}+\ldots+a_{99}$?
(A) $\frac{5}{4}\left(1-0.8^{50}\right)$
(B) $\frac{5}{4} \cdot 0.2^{50}$
(C) $\frac{5}{4}-0.2^{50}$
(D) $\frac{5}{4}\left(1-8 \cdot 10^{-50}\right)$
(E) $5 \cdot 0.2^{48}$
(A) $\frac{5}{4}\left(1-0.8^{50}\right)$
(B) $\frac{5}{4} \cdot 0.2^{50}$
(C) $\frac{5}{4}-0.2^{50}$
(D) $\frac{5}{4}\left(1-8 \cdot 10^{-50}\right)$
(E) $5 \cdot 0.2^{48}$