QUESTION $4$

$4\mathrm{.}1$ A system has $4$ components, $A,B,C,$ and $D,$ with reliability values of $0\mathrm{.}98,0\mathrm{.}89,0\mathrm{.}94,$ and $0\mathrm{.}95,$ respectively. If the components are in series, what is the system reliability?

$(5)4\mathrm{.}2$ A system has $3$ components, $A,B,$ and $C,$ with reliability values of $0\mathrm{.}986,0\mathrm{.}899,$ and $0\mathrm{.}945,$ respectively. Determine the system reliability when the components are arranged in parallel.

$(5)$