probability of being hemophiliac and daughter is zero because females have 50% chance of being carrier.
where as males have 50% chance of being affected with hemophilia.
example for understanding: if after mating a girl have X chromosomes with hemophilia gene than she might have hemophilia but that is in rear case so probability is zero.
So 1/2x+2=2/3x convert to common fraction 1/2=3/6 2/3=4/6 3/6x+2=4/6x subtract 3/6x from both sides 2=1/6x multiply boh tisdes by 6 12=x the tank can hold 12 gallon
