12. supplier x offers a mechanic a part at 35% off the retail price of $66.40. supplier y offers him the same part at 20% over the wholesale cost of $39.20. which is the better deal, and by how much? select the correct choice below and fill in the answer box to complete your choice. (type a whole number or an exact decimal. if the decimal does not terminate, round to two decimal places.) a. supplier x offers the better deal by $ b. supplier y offers the better deal by $