Carmen decorates 8 plates with 1 whole sprig of parsley, 8 plates x 1 parsley sprig each = <<8*1=8>>8 parsley sprigs.
She also decorates 12 plates with 1/2 a sprig each, 12 x 1/2 = <<12*1/2=6>>6 parsley sprigs.
She started with 25 parsley sprigs and has used 8 + 6 = 14 parsley sprigs.
After using 14 parsley sprigs, she has 25 - 14 = <<25-14=11>>11 sprigs left.
#### 11