File "Ageing" Shell Script

A) Create a shell script that will calculate the number of files in your account hat were last modified five or more days ago and when you run the shell script, results should look something like this:

% ageing
there are 19 files modified 5 or more days ago.
%

B) Modify your script (or re-write it if you wish) to allows the user to choose what the script should use for the last modified day. Example:

% ageing 15
There are 4 modified files 15 or more days ago.

C) Modify the script to get it to back up to "X" number of days and list the files that were modified for each day. Example:

% ageing -3
Files modified 1 day ago
./a.txt
./b.txt

Files modified 2 days ago
./2days.txt
./dir1/test_file.txt
./dir2/test_file2.txt

Files modified 3 days ago
(none)