# We've Got Your Numbers Quiz

By: Alia Hoyt
1 min
Image: Kristin Lee/Getty Images

Whether you're a math whiz or not, there are some pretty cool number theories, beliefs and coincidences to appreciate. How down with digits are you?
What was the last number that mathmeticians finally figured out how to express as the sum of three cubes?
33
42
In 2019, mathemetician Andrew Booker figured out how to express 33 as the sum of three cubes (33 = x³+ y³+ z³). Later that same year, Booker and MIT professor Andrew Sutherland used the same code to solve the Diophantine Equation (x^3+y^3+z^3=k) for the lone remaining integer under 100 that hadn't been conquered: the number 42. Scientists had been trying to do this for more than 60 years.
111
What number's mystical significance might have started with a story from author William Burroughs?
47
13
23
The famed writer may have kicked off the obsession with the number 23 thanks to his short story "23 Skidoo," inspired by a series of bizarre occurrences he had involving the number. There's even a Facebook page, "23rdians," populated by people who believe in 23's significance.
After age 30, how much more likely is the average person to die?
The risk of death doubles every eight years.
Actuary Benjamin Gompertz developed a "mortality equation" in 1825 which is still used today to help insurance companies figure out how to buy and sell annuities. He calculated that the odds of a person dying roughly doubles every eight years.
The death risk doesn't take a big leap until age 50.
The risk of death triples after age 40.

If someone asks you to guess what their favorite number is, which of these should you guess?
3
7
You might have the most luck guessing number 7. A 1971 study, known as the "blue-seven" phenomenon, found that 30 percent of respondents said their favorite number was 7, while 40 percent said their favorite color was blue! This was consistent across countries.
5
Where did fear of the number 666 originate?
"Carrie" by Stephen King
the New Testament's Book of Revelation
One verse in particular reads, “One who understands can calculate the number of the beast, for it is a number that stands for a person. His number is six hundred and sixty-six” (Rev. 13:18). The beast refers to the Antichrist.
Dante's "Inferno"
What type of numbers are often used to complete secure credit card transactions?
prime numbers
Prime numbers, which are divisible only by one and itself, appear random, and are thusly used to encrypt information exchanged over the internet.
irrational numbers
square numbers

What is a "perfect number"?
a perfectly symmetrical number, like 8
a positive integer equal to the sum of its proper divisors
The smallest of all the perfect numbers is 6, which is the sum of its divisors, 1, 2 and 3.
an answer which has no remainder at the conclusion of a division problem
No matter the size of the circle, the ratio of circumference to diameter will always equal 3.14.
Pi is the ratio of the circumference of a circle to its diameter. The amazing thing is whether you're measuring a planet or a tennis ball, the number will always be 3.14.
As a circle doubles in size, pi will also double.
It tastes great with a cup of coffee.
Evolutionary biologist Robin Dunbar said the human brain can't handle more than this number of friends:
150
Dunbar's number as its called, was based on his research showing that hunter-gatherer societies were comprised around 150 people.
100
200