[tex] \frac{1}{4} [/tex]
because there mother is colorblind c is carrier gene and b is colorblindness gene
[tex]x^{c} {x}^{b} [/tex]
and their dad isn't so
[tex] {xy}[/tex]
chances:
[tex] {x}^{c} {x}[/tex]
normal vision daughter and a carrier
[tex] {xx}^{b} [/tex]
colorblind daughter
[tex] {x}^{c}y[/tex]
normal vision son and a carrier
[tex] {x}^{b} y[/tex]
colorblind son
