Problem $5$: $(5$ marks$)$

A power system is to be designed with an overall $($total$)$ reliability $R_T=0\mathrm{.}980.$

Using components having individual reliabilities of $0\mathrm{.}8,$

Question $1$: $(2$ marks$)$

What is the minimum number of components that must be connected in parallel?

Question $2$: $(3$ marks$)$

$1-$What would be the number of components if they were to be connected in series?

$2-$Justify your answer.