If there's no discount, adding all prices generates a total of $18.72.
To get the discounted percentage, we need to get the equivalent price rate per discount of each items.
Chicken: $8.47 x 0.15 = $1.27
Milk: $2.16 x 0.20 = $0.43
Onions: $0.89 x 0.10 = $0.09
Potato chips: $1.45 x 0.12 = $0.17
Oranges: $1.36 x 0.25 = $0.34
Flour: $4.39 x 0.18 = $0.79
Next, we will add discounted price equivalents and it will give us a value of $3.09. To get his total percentage discount, we expressed it as: $3.09 / $18.72 x 100 = 16.50%. So, Jan gets a total discount of 16.50%.
