Trivia

Hard

In Your Average School Class There Is A 50% Chance Two People Share What?

Blood Type
Great-Great-Great Cousins
Ear Wax Type
A Birthday
A graph depicting Birthday Paradox calculations.
Rajkiran g/Wikimedia

Answer: A Birthday

In the field of probability theory, there is a problem known as the Birthday Paradox concerning the probability that in a selection of N randomly chosen people, some of them will share a birthday. This probability reaches 100 percent once you reach a sample size of 367 people (to account for the 366 potential days, including Feb. 29th, +1).

What’s fascinating, however, is how quickly the probability of sharing a birthday climbs. In a group of 23 people, around the size of a small class, the chances of two people sharing a birthday have already climbed to 50 percent. To get to 99 percent, you’d just need to gather two classrooms together. In a group of 57 people, there is a 99 percent chance that there is a common birthday.

While this might seem like something of a mathematical parlor trick, the math behind the Birthday Paradox has actually been successfully employed as a well known cryptographic attack, the Birthday Attack, which uses probabilistic modeling to reduce the complexity of cracking encryption hash functions.

Trivia

Hard

What Office Ritual Is The Result Of Careful Marketing?

Trivia

Easy

When Divers Get “The Bends”, It’s Triggered By A Buildup Of?

Trivia

Hard

The Periodic Table Of Elements Was Inspired By What?

Trivia

Hard

Tamagotchis, The Fad “Pocket Pet” Toy That Swept The Late 1990s, Was Created By What Company?

Trivia

Easy

Having Your Appendix Removed Is A Prerequisite For Working Where?

Trivia

Hard

Which Of These Bowling Variants Is Extremely Popular In Eastern Canada And The New England Area?

Trivia

Easy

What Common Beer Brewing Ingredient Is In The Marijuana Family?

Trivia

Hard

The Skinny Tie Entered American Culture As A Result Of?

Trivia

Hard

Tapping On A Ketchup Bottle With A Knife To Extract The Ketchup Works Because Of?