Who Shares Your Birthday?

The video explores the probability of shared birthdays, known as the birthday paradox, and explains how few people are needed for a high chance of shared birthdays. It uses examples like paper folding to illustrate exponential growth and discusses the probability of sharing a specific birthday. The video also examines how many Facebook friends are needed to cover all birthdays, highlighting the challenges of probability and exponential growth.

What is the probability that two people in a group of 44 share the same birthday?

• 50%

• 93%

• 25%

• 75%

How many people are needed in a room to have a greater than 50% chance of sharing a birthday?

• 50

• 44

• 365

• 23

What is the probability that three people in a room have unique birthdays?

• 50%

• 25%

• 99.2%

• 75%

How many times must you fold a piece of paper to reach the moon?

• 10

• 42

• 100

• 50

To have a 90% chance of someone sharing your birthday, how many people are needed?

• 500

• 365

• 840

• 1000

How many friends are needed on average to have a birthday on every day of the year?

• 1,000

• 365

• 500

• 2,153

To have a 90% chance of covering all birthdays, how many friends would you need?

• 10,000

• 5,000

• 15,000

• 21,000