For every one dozen flowers bought, a customer gets 2 free flowers. If Maria wants to buy 3 dozens flowers, how many pieces of flowers will she have in all?
Maria has 3 x 2 = <<3*2=6>>6 free flowers from buying 3 dozens flowers.
Since each dozen is equal to 12, then Maria bought 3 x 12 = <<3*12=36>>36 flowers.
Hence, she has a total of 36 + 6 = <<36+6=42>>42 flowers.
#### 42