Plz solve Q no. 9 for 2 mark question

Plz solve Q no. 9 for 2 mark question 8 lityo Inn e ecomtnga Rakesh 's parents have rwnnal colour vision. But his maternal grandfather is possibility ofRakesh and his siblings trcoming colour blind'? the following :

as maternal grandfather is colourblind, his genotype is -X^oY
parents have normal vision, therefore-
mother- X^oX
father- XY

the possibility of Rakesh and his siblings becoming colourblind is-

Therefore, the phenotypes are-
colourblind son, carrier daughter, normal daughter and normal son.
Hence, the possibility of Rakesh and his siblings becoming colourblind is 25%