1 .
Consider a standard 6-sided fair die. We roll this die 8 times. Let $A$ be the event
- A = "there are at least two 5's in the sequence of 8 rolls".
(a)
$1 - {\frac{5^{8} + 8 \cdot 5^{7}}{6^{8}}}$
(b)
$1 - {\frac{6^{8}}{5^{8} + 8 \cdot 5^{7}}}$
(c)
$1 - {\frac{8 \cdot 5^{7}}{6^{8}}}$
(d)
$1 - {\frac{8^{5} + 8 \cdot 7^{5}}{8^{6}}}$