SOLUTION: Your mathematics teacher displays a monthly calendar which highlights all the birthdays of your classmates. Your mathematics class has 25 students. What is the probability that 3 o

Algebra ->  Probability-and-statistics -> SOLUTION: Your mathematics teacher displays a monthly calendar which highlights all the birthdays of your classmates. Your mathematics class has 25 students. What is the probability that 3 o      Log On


   

Question 917993: Your mathematics teacher displays a monthly calendar which highlights all the birthdays of your classmates. Your mathematics class has 25 students. What is the probability that 3 or more students were born in the same month ?
Help me please my math teacher didn't show us any of this!
Answer by KMST(5328) About Me  (Show Source):
You can put this solution on YOUR website!
If you try to distribute birthdays evenly to minimize the number of birthdays in each month, you could accommodate 24 students in the 12 months of the year so that each month would just have 2 birthdays:
2%2A12=24 .
However, the 25th student would need a birthday in any of the month that already had 2 birthdays.
You cannot avoid having 3 birthdays in one/some month.
It will happen.
It is a sure thing.
The probability that at least 3 (or more) students were born in some (the same) month is 1.00 (or 100%, whichever way you choose express probability).