Question

Find the probability that 4 randomly selected people all have the same birthday. Ignore leap years. Round to eight decimal places.

Answer 1

The number of days of not leap years is 365.

So, the number of different variations of birthdays for 4 people is 365 * 365 * 365 * 365 = (365)^4

The probability that all of them be one specific day is 365 / (365)^4 = 1 / (365)^3 ≈ 0.00000002.

Answer: 0.00000002