Hello and welcome to MHB! :D
First, I want to point out a couple of issues...I moved your thread from the Chat Room to our Basic Probability forum as this is a better fit for your question. The Chat Room is for informal discussions about pretty much anything, and we ask that actual math problems be posted in the appropriate forum so that MHB is more useful for everyone.
Your original thread title did not indicate anything about the nature of your question. Again, doing so makes MHB more useful for everyone.
Lastly, we do ask that you show what you tried so that we can see where you are stuck and/or where you may be going wrong, and then we can offer guidance to get you unstuck.
Okay, now let's look at the problem. We know that the probability will be the number of favorable outcomes divided by the total number of outcomes.
Favorable outcomes: How many ways can a person's birthday be in the given rage?
Total outcomes: How many ways can a person have a birthday in January?