Question 998418
Early Bird:
He will get .20 discount for every dollar he spends (20% means 20 per one hundred). Thus, instead of paying 1 he will pay 1-.20= .80. The amount he spends is unknown, let's call it x. So he will pay:
.80x
Additionally, he gets a 15 discount for spending over 100:
.8x-15 is the cost of Rifah's purchase.