Question

Rearrange the following steps in the correct order to find the probability that in a group of n people chosen at random, there are at least two born on the same day of the week.

Rank the options below.

Each person after the first must have a different birth day of the week from all the previous people in the group
The probability that at least two are born on the same day of the week is therefore 1-pn.
The probability that all the birth days of the week are different is pn=6/7, 5/7,.... 8-n/7

Answer 1

The correct sequence would be:

Step 1 -> Step 2 -> Step 3

Here's the rearranged order of the steps:

The probability that all the birth days of the week are different is

pn=6/7, 5/7,.... 8-n/7 .

Each person after the first must have a different birth day of the week from all the previous people in the group.

The probability that at least two are born on the same day of the week is therefore 1−p_n .

So, the correct sequence would be:

Step 1 -> Step 2 -> Step 3