The probability of being born in May or on the 30th of any month
We have 12 months in a year
Probability of being born in may is 1/12
It is 1/12 because we only have one May in a year
OR 30th of every month
Out of all the months, only 11 months are upto 30 except February
The probability of being born on the 30th of any month is 11/12
In probability, or means addition
Therefore, we have
1/12 + 11/12
0.083 + 0.9166
= 0.9996
The answer is 0.9996 or approximately 1