What is the probability that at least two persons out of a group of three persons were born in the same month (disregard year)?

What is the probability of two persons being born on the same day ?

The probability that out of 10 person,all born in June,at least two have the same birthday is

If three people are chosen ata random, then the probability that no two of them were born in the same date of the month of september is

There are three persons aged 50,60 and 70 years.The probability to live 10 years more is 0.8 for a 50 years old 0.5 for a 60 years old and 0.2 for a 70 years old person.Find the probability that at least two of the three persons will remain alive 10 years hence.

There are three persons aged 50, 60, and 70 years. The probability to live 10 years more is 0.8 for a 50 years old, 0.5 for as 60 years old and 0.2 for a 70 years old person. Find the probability that at least two of the three persons will remain alive 10 years hence.