If ‘X & Y’ indicates that X is the brother of Y, ‘X % Y’ indicates that X is the father of Y, and ‘X # Y’ indicates that X is the wife of Y, then which of the following describes the relationship of M to O in the expression ‘M % N # O’?

The correct option is: M is the father-in-law of O.

To determine the relationship of M to O in the given expression, let us decode the symbols step-by-step based on the rules provided in the question:

1. 'X % Y' means X is the father of Y.
2. 'X # Y' means X is the wife of Y.
3. 'X & Y' means X is the brother of Y.

Now, let us analyze the given expression: ‘M % N # O’

Step 1: Decode 'M % N'
From the rule 'X % Y', 'M % N' means M is the father of N. This implies M is male.

Step 2: Decode 'N # O'
From the rule 'X # Y', 'N # O' means N is the wife of O. This implies N is female and O is her husband (male).

Step 3: Determine the relationship between M and O
Since M is the father of N, and N is married to O (with N being the wife of O), M is the father of O's wife.
Therefore, M is the father-in-law of O.