Answer:
A)144/133225
B)1/365
Step-by-step explanation:
A) We want to find the probability that two people have a birthday on the 18th of any month.
If we Neglect leap year like the question says, it means that there are 365 days in a year.
Now, we have 12 possible number of 18th day in all months that make a calendar year.
Thus;
If two people have birthday on 18th, the probability that the two of them will have birthday on the 18th of any month is;
P(both to have birthday on the 18th of any month) = (12/365) × (12/365) = 144/133225
B) We want to find the probability that two people have a birthday on the same day of the same month. This can be written as;
P(2 people have a birthday on the same day of the same month) + P(2 people do not having birthday on same day of same month) = 1
Probability of 2 people not having birthday on same day of same month = 365/365 × 364/365 = 364/365
P(2 people have a birthday on the same day of the same month) = 1 - (364/365) = 1/365
