Community Spring Cleaning week is here! Join your fellow Maveryx in digging through your old posts and marking comments on them as solved. Learn more here!

Weekly Challenges

Solve the challenge, share your solution and summit the ranks of our Community!

Also available in | Français | Português | Español | 日本語
IDEAS WANTED

Want to get involved? We're always looking for ideas and content for Weekly Challenges.

SUBMIT YOUR IDEA

Challenge #140: Prove the Birthday Paradox!

pasccout
8 - Asteroid

Here is my solution

challenge_140.jpg

datatim
7 - Meteor
 
AGoyal
8 - Asteroid

Solved. Bit lengthy and complex, but gets the job done.

 

 

NicoleJohnson
ACE Emeritus
ACE Emeritus

My solution!

 

NOTE: Was way easier after I realized that "same birthday" meant people who celebrate their birthday on the same day, not people who were born the exact same day AND year. (In case you are wondering, the birthday paradox does not apply to scenario #2... though with a group size of 50, and an assumed average life expectancy of 75 years, turns out there is actually still a ~5% chance that two people were born on the exact same day!)

 

Spoiler
WeeklyChallenge140.JPGShowing 50% probability that birthdays will be shared at a group size of 23... probability increases to 75% around group size of 32, and 90% at 41 people!Showing 50% probability that birthdays will be shared at a group size of 23... probability increases to 75% around group size of 32, and 90% at 41 people!

Cheers! And since the data seems to indicate there's a pretty good chance it's someone's birthday today with a Community this size... happy birthday, whoever you are! :)

 

NJ

PhilipMannering
16 - Nebula
16 - Nebula

Again, loving the Interactive Chart tool. My solution below,

 

Spoiler
WorkflowWorkflowMacroMacroChallenge 140 - Capture.PNG
jamielaird
14 - Magnetar

Here's my solution. I went for a batch macro. Really enjoyed this one!

 

Spoiler
Main workflowMain workflowBatch macroBatch macroProbability scatter plotProbability scatter plot

 

 

sidneyjacobs
7 - Meteor

Avoided using macros in order to solve this challenge, got a pretty elegant workflow regardless.

 

Preview of workflow:

Spoiler
workflow.PNG

Preview of the results:

Spoiler
Capture.PNG
RolandSchubert
16 - Nebula
16 - Nebula

My solution

ipeng
8 - Asteroid
Spoiler
Challenge 140.PNG

Interesting practice

justin_winter
8 - Asteroid

Pushed this one pretty hard... Ran 100,000 simulations each for both Leap Years and Non Leap Years, then weighted the Leap Years 97/400 and non Leap Years 303/400 (Based on a prior calculated 400 year Leap Year cycle calculation). Then ran the precision out to 10 decimals! Had fun with this one!! With 100K simulations the curve smooths out pretty nicely.

 

Birthday duplicate curve.png