Answer :
He pays 15.40$ because the coupon code is 6$ and the sales tax is 1.40$
The calcul is 30/100= 0.30
0.30 x 20 = 6$
20 - 6 = 14$
Use the same method for the taxes expect addition them to the price
The calcul is 30/100= 0.30
0.30 x 20 = 6$
20 - 6 = 14$
Use the same method for the taxes expect addition them to the price