Answer:
13
Step-by-step explanation:
This problem is an example of pigeonhole principle which states that If n+ 1 objects are placed into n boxes, then some box contains at least 2 objects.
Here no. of months in a year are boxes n = 12.
Therefore number of objects( people) = n+1= 13.
Then,at least two people in the group whose birthdays fall in the same month.
