ihatethis

ok, so im vary frustrated with this...please help me. i already know the answer, i just dont know how to get it. a trihybrid pea plant, having the genotype AaBbCc is self fertilised. all loci are unlinked. there is complete dominance at the A and B loci, but incomplete dominance at the C locus. the fraction of progeny that will be phenotypically diffrent from the parent is... the correct answer is 23/32. how do i get this answer? also here is another one im stuck on, phenylketonuria, a metabolic didorder in humens, is inherited a san autosomal recessive trait. a husband and a wige, noth hererozygous for the gene, plan to have six childred. what is the probability that, in any order, gour of the offspring will be normal and two will have phenylketonuria? please tell me the steps to solving these problems if you know them. thanks