In total, there are 4 x 4 = <<4*4=16>>16 pizza pieces.
Bill and Dale eat 2 x 4 x 50% = <<2*4*50*.01=4>>4 pieces.
Ann and Cate eat 2 x 4 x 75% = <<2*4*75*.01=6>>6 pieces.
The four of them eat 4 + 6 = <<4+6=10>>10 pieces.
There are 16 - 10 = <<16-10=6>>6 pizza pieces uneaten.
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