# MATH, HELP

what is the probability that at least 2 students in a class of 36 have the same birthday?

Do i punch this in to the calculator or how did you found this way or method for your solution:

Log(365!) = 1792.3316

Log(329!) = 1581.7202

36 Log(365) = 212.3963

And therefore:

365!/[(365-36)! 365^36] =

Exp[1803.9383 - 1581.7202 - 212.3963] =

Exp[-1.7849] = 0.16781

1 - 0.16781 = 0.83219

THAT IS THE SOLUTION BUT I WANT TO UNDERSTAND THE STEPS FOR IT...CAN SOMEONE EXPLAIN THEM TO ME PLEASE...

Start with any student, he/she obviously will have a birthday (365/365 or probability is 1)

Now conider the second student. The probability that he/she will have a DIFFERENT birthday is (365/365)(364/365).
Now the third student's probability of having a DIFFERENT birthday is
(365/365)(364/365)(363/365)

Continuing this argument until we reach the last student to have a different birthday from all the rest we have
(329/365)(330/365)....(364/365)(365/365)

This is the probability that everybody will have a DIFFERENT birthday, so the the probability of NOT DIFFERENT, or at least somebody having the same birthday is 1 - the above multiplication.

I will let you finish the actual calculation.

yha um can you help me with my math

1. 👍 0
2. 👎 0
3. 👁 141
1. test

1. 👍 0
2. 👎 0
posted by dan
2. <>"'/\?[]{}&%#@()

1. 👍 0
2. 👎 0
posted by dan

1. 👍 0
2. 👎 0
posted by dan

## Similar Questions

1. ### Geometry

When Ms Shreve randomly selects a student in her class, she has 1/3 probability of selecting a boy. A: If her class has 36 students, how many boys are in her class? B: if there are 11 boys in her class, how many girls are in her

asked by Anonymous on September 18, 2017
2. ### 10th Grade Math

A history class is comprised of 6 female and 9 male students. If the instructor of the class randomly chooses 5 students from the class for an oral exam, what is the probability that 2 female students and 3 male students will be

asked by Jonathan on August 30, 2016
3. ### statistics: dependent event

A psychology class is comprised of 4 female and 6 male students. If the instructor of the class randomly chooses 6 students from the class for an oral exam, what is the probability that 2 female students and 4 male students will

asked by John on February 22, 2011
4. ### Statistics

A history class is comprised of 5 female and 8 male students. If the instructor of the class randomly chooses 8 students from the class for an oral exam, what is the probability that 2 female students and 6 male students will be

asked by Ryan on March 10, 2015
5. ### Math

In a math class there are 28 students. Each student has a 90% chance of attending any given class and students act independently. What is the probability that tomorrow's class has perfect attendance?

asked by Cortney on March 22, 2012
6. ### math/probability

For some reason I can not get my head around probability. Please show me how to work the problem not just the answers. A class has 11 students who are to be assigned seating by lot. What is the probability that the students will

asked by Jaime on July 24, 2010
7. ### statistics

In this summer school class there are 28 male students and 15 female students. An experiment is done that consists of selecting a student at random, and recording their gender. This is done 4 times WITH REPLACEMENT. 1) Fill in the

asked by david on July 9, 2011
8. ### Language

in the excerpt from barrio boy, what makes Ernesto smilar to several of his classmates? A. Other students in the class also do not speak English.•• B. Other students in his class also live in his neighborhood. C. Other

asked by Amanda on January 11, 2016
9. ### statistics

In a recent survey in a Statistics class, it was determined that only 60% of the students attend class on Thursday. From past data it was noted that 98% of those who went to class on Thursday pass the course, while only 20% of

asked by bilal on November 21, 2011
10. ### Business Stats

In a recent survey in a Statistics class, it was determined that only 60% of the students attend class on Fridays. From past data it was noted that 98% of those who went to class on Fridays pass the course, while only 20% of those

asked by Jada on March 13, 2013
11. ### math

Mr. Hauseman has 17 students in his class, three of whom are freshmen, and the rest are from other classes. He is going to draw two students randomly to be partners. He calculates the probability of drawing a freshman and then a

asked by tymeasha on May 3, 2019

More Similar Questions