Understanding the Birthday Paradox

What is the probability that two randomly selected people share the same birthday?

• 0.3%

• 1%

• 10%

• 5%

What is the minimum number of people required in a room for there to be a greater than 50% chance that at least two share a birthday?

• 30

• 50

• 23

• 15

Why does the Birthday Paradox seem counterintuitive?

• Because it contradicts common sense.

• Because it involves complex math.

• Because people often miscalculate probabilities.

• Because 365 days seem like a lot of options.

How many pairs of people can be formed from a group of 23?

• 365

• 100

• 46

• 253

What is the probability that none of the 23 people in a room share a birthday?

• 70%

• 60%

• 49%

• 51%

What is the probability that at least two people share a birthday in a room of 23 people?

• 90%

• 51%

• 70%

• 30%

How many people are needed in a room for a 99.9% chance that at least two share a birthday?

• 23

• 100

• 75

• 50

What principle explains why 366 people guarantee a shared birthday?

• Certainty Principle

• Birthday Principle

• Pigeonhole Principle

• Probability Principle

What is the probability that at least two people share a birthday in a room of 75 people?

• 99.9%

• 80%

• 60%

• 50%

How many people are needed for a 100% chance of shared birthdays?

• 368

• 366

• 367

• 365