Class Activity

Instruction: Work with a neighbor to answer the following questions. Solutions will be posted on the course website. To get started, download the class activity template file.

The birthday problem

Suppose we have a class of 30 students. What is the probability that there is at least one shared birthday?

Assume there are 365 days in a year
Assume that each day is equally likely as a birthday
Assume there are no multiple-birth siblings (e.g. twins, triplets, etc.) in the class

Use the np.arange function to create a 1-dimensional array, days, to store the days of the year (numbered 0 to 364)
Use the np.random.choice function to randomly choose birthdays for the class (shared birthdays are possible, so use replace=True in the function!)
Check the number of distinct birthdays (hints: the np.unique and len functions may be helpful!). Are there 30 distinct birthdays?
Use a for loop to repeat the experiment nsim = 10000 times, making sure to store the results. What is the probability of at least one shared birthday?