Question

A non-haemophilic couple was infomed by their doctor that there is possibility of a haemophilic child being born to them .Draw a checker board and find out the percentage of possibility of such a child among the progeny.

Answer 1

The couple themselves are non-haemophilic. Thus , the mother must be a carrier and father must be normal .
50% daughter normal (XX)
50% daughter carrier `(XcancelX)`
50% son normal (XY)
50% son haemophilic `cancel(XY)`