Given: S1 and S2 are two swiches whose probabilities of working be given by
P(S1) =
2
3
and P(S2) =
3
4
To Find: the probability that the current flows from terminal A to terminal B when
S1 and S2 are connected in parallel.
Now, since current in parallel flows in two or more paths and hence the sum of currents through each path is equal to total current that flows from the source.
⇒
the flow of current from terminal A to terminal B in a parallel circuit is given by
=
11
12
Therefore, The probability that the current flows from terminal A to terminal B when S1 and S2 are connected in parallel is
11
12
