I’ve read it so many times that the paper has gone soft at the creases. If it were a library book, I’d owe fees.
“I’ll take whatever’s left over,” I say.
Dan’s eyebrows rise.
I hold back for the first few rounds. I really do.
I only wait until no one else knows the answer, then I suggest an answer like I’m not completely confident it’s correct.
But in round four, the quizmaster asks which nineteenth-century surgeon performed the only operation in history with a three hundred percent mortality rate—killing the patient, the assistant, and a spectator—and the table goes silent. Priya shrugs.
“Robert Liston,” I say. “1847. He amputated the leg in under two and a half minutes, but he was so fast that he slashed through his assistant’s fingers and caught a spectator’s coat with the blade. The patient and the assistant died of gangrene. The spectator dropped dead of shock.”
The silence at our table is different now. Shit. I got a bit carried away there.
“How do you know that?” Jaymee asks.
I shrug. “It’s the kind of story that sticks in your brain.”
But at the end of the round, there’s a random bonus question.
“How many people need to be in a room for there to be a greater than fifty percent chance that two of them share the same birthday?”
“I think it’s one hundred and eighty-three?” Priya says. “Roughly half of three hundred and sixty-five?”
I open my mouth. Close it. Open it again.
“It’s twenty-three,” I say.
Billy laughs. “Twenty-three? In what universe is it twenty-three?”
“No offense, mate, but she’s a science teacher, so I think we’re going to go with her on this one,” Dan says.
I lean back. “Fair enough.”
“Hang on a sec,” Jaymee says. She looks at me curiously. “Archie, what makes you say it’s twenty-three?”
I hesitate.
You’re not too much.
“Because you’re not calculating the odds of someone sharing your birthday. You’re calculating the odds of any two people in the room sharing any birthday. With twenty-three people, there are two hundred and fifty-three possible pairs. And so you work out the probability that none of those two hundred and fifty-three pairs match, which means multiplying three hundred and sixty-four over three hundred and sixty-five by three hundred and sixty-three over three hundred and sixty-five and so on until it crosses the fifty percent threshold at twenty-three.”
Dan still has a big grin on his face like it’s all a massive joke. Jaymee is side-eyeing me with a weird expression.
“Actually, he might be right,” Priya says. “That logic checks out, I think.” She gives me a puzzled look.
“So we’re going with Archie’s answer?” There’s still skepticism in Dan’s voice.
Jaymee flicks a glance at me. “If you’re certain, Archie?”
“Yeah, I am.”
We hand in our answer sheet, and while we’re waiting for it to be checked, Priya gets out her phone.
“He’s definitely right,” she says. “The answer is twenty-three.”
Dan gives me a strange look. “Are you one of those weird people who understands math intuitively? Like Matt Damon inGood Will Hunting?”
