A grocer professes to sell his homemade cooking oil at the cost price, but he mixes it with vegetable oil, which he gets for free and
thereby, gaining 30%. The approximate percentage of vegetable oil
in the mixture is:

total amount to be paid = $19.5

step-by-step explanation:

given ,

original price = $25.99

discount = 25%

discount amount = 25% of original price

discount amount = 25/100   * 25.99

discount amount = $6.49

hence , the total amount to be paid = original price - discount amount

                                                            = $25.99 - $6.49

                                                            =$19.5

total amount to be paid = $19.5