Trivia

Hard

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

Ear Wax Type
A Birthday
Great-Great-Great Cousins
Blood Type
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’s The Most Popular Screen Resolution Among Internet Browsers?

Trivia

Easy

What Color Were Early Automobile Tires?

Trivia

Easy

“Peace Lines” Are An Urban Architectural Feature Found Throughout?

Trivia

Very Hard

The Oligodynamic Effect Is A Phenomenon That Describes?

Trivia

Hard

The Oldest Known Trees Are All Members Of What Species?

Trivia

Hard

Which Of These U.S. States Has The Largest Water To Land Ratio?

Trivia

Hard

The Word “Boycott” Entered The English Language By Way Of?

Trivia

Hard

In 2007 A Radio Show Contestant Died Of Water Intoxication In A Bid To Win A?

Trivia

Hard

To Give Their Eggs An Advantage, Some Butterflies Have Evolved To?

Trivia

Hard

Bubble Wrap Was Originally Invented To Serve As What?