An electronic assembly consists of two subsystems, say A and B. From previous testing procedures...

An electronic assembly consists of two subsystems, say A and B. From previous testing procedures, the following probabilities are assumed to be known :
\[
\begin{array}{ll}
\mathrm{P}(\mathrm{A} \text { fails }) & =0.2 \\
\mathrm{P}(\mathrm{B} \text { fails alone }) & =0.15 \\
\mathrm{P}(\mathrm{A} \text { and } \mathrm{B} \text { fail }) & =0.15
\end{array}
\]
Evaluate the following probabilities: P (A fails alone)