Amother has one alleles for dimples and one allele or no dimples. what is the probability that she produces a gamete with the allel for dimples

We can use genetic probability here to determine the chance of producing a gamete that has an allele for dimples. The matrix of probability is shown below where capital letters are attributed to the woman and small ones is that of men. We can see then that the probability of having an allele for dimples is 3/4 having the only chance of not having one is Bb.  

Aa
Ab
Ba
Bb

Ithink it’s around 500 million or something. kinda scary honestly but that’s just my opinion.