A XYZ system consists of sub$-$system $)=(0\mathrm{.}75$ sub$-$sysiom $)=(1\mathrm{.}0,$ sub$-$system $E)=(0\mathrm{.}1$ and sub$-$system $R(-0\mathrm{.}10)$

connocted in series. Calculate the probabity of losing the forw measurement after $0\mathrm{.}5$ year for the following:

a$)$ A single flow measurement syrstem.

$[5$ marks$]$

b$)$ Three identical flow measurement systems in parallel.

$[5$ marks$]$

c$)$ A system with three sub$-$system $"$O$",$ three sub$-$system T$"$ and a single middle value selector $($

$=0\mathrm{.}1).$ The selector selects the average output signal. The selected signal is then paseed to sub$-$system $"$E$"$ and sub$-$systern $"$R$".$

$[10$ marks$]$

d$)$ What conclusions can be drawn from these calculations?

$[5$ marks$]$