Solution:
We assume that denote mother, denote father and denote son.
Then, the sample space for the given experiment will be:
S= { MFS, SFM, FSM, MSF, SMF, FMS }
The events given are E: Son on one end
& F: Father in middle
Sample space of the following are:
and
The probability of the event,
Now, we know that by definition of conditional probability,
Now by substituting the values we get