In "Outsiders", what does it mean when Two-Bit says "you're 96 if you're a day," and Marcia replies "I'm a night"? Chapter 2
Through this exchange between Two-Bit and Marcia, the author is giving the reader insight into the character of Marcia. Although she is a nice girl, she does not have the depth or intelligence that Cherry has.
Two-Bit is speaking to Ponyboy and Johnny, who are the young ones of the gang, teasing that Cherry and Marcia look to be a little older. He makes the comment about the girls being "ninety-six if (they're) a day", to which Marcia, in a rather lame attempt at being funny, "brightly" responds, "I'm a night". Two-Bit "admiringly" rejoins, "Brother, you're a sharp one".
The author is trying to accentuate the difference between Cherry and Marcia with this exchange. Marcia, like Two-Bit, tends to be careless, and to live in the moment; Two-Bit thoughtlessly scares the already traumatized Johnny out of his wits, and Marcia, who had a moment earlier been furious at Dally's rude behavior, nonchalantly accepts his Coke. Cherry, in contrast, is intelligent and deeply perceptive, like Ponyboy. She picks up nuances about people and situations, understanding that Ponyboy and Johnny are sensitive about their age, deflecting Marcia's unintentionally hurtful observation that the boys look fourteen, appreciating that they want just to hang out and not "make out for the night", and sticking to her principles in not accepting Dally's Coke (Chapter 2).