M: May I have that type please? How much does it cost? ,F: It's $30. But today we offer a 10% discount, if you purchase more than 3.
(A) M: Great! I'll pay $108 by card. (B) M: I didn’t hear you. Please could you tell me again? (C) M: Wow, it's quite expensive. I'll get two for $108, as you said each type is 54 dollars. (D) M: Okay. After 10% discount, i'll pay you $120 for four types.
A