Need a little help and guidance:

Tennis match. Player A to hold serve is 85%, Player B to hold serve is 80%.

What is the probability that player A will win 6-0?

I have converted the percentage into fractions so to hold serve the odds are 3/17 and to break serve the odds are 4/1, is this correct. if we then multiply through the 3 holds and 3 breaks i get 1728/4913 which equates to 73.98%. This seems high, have i gone wrong here?