Julia owns 3 * 20 = <<3*20=60>>60 bronze watches.
60+20 = <<60+20=80>>80 total silver and bronze watches
10% of all Julia's watches is 80 * 10/100 = <<80*10/100=8>>8 watches, and she decided to buy so many gold watches.
So in total Julia is in possession of 20 + 60 + 8 = <<20+60+8=88>>88 watches.
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