21.
In a certain code language,
‘A + B’ means ‘A is the mother of B’;
‘A – B’ means ‘A is the brother of B’;
‘A x B’ means ‘A is the wife of B’ and
‘A ÷ B’ means ‘A is the father of B’.
Based on the above, if M + Q – R + K – Y, then how is M related to Y?