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17. I have a directory called "~/MyFiles." It's owned by user 'pc' and group 'pc.' Change the ownership so that it is now owned user 'super' and group "secret". (5 points) 18. Create a crontab entry that would run the file /etc/clear.sh every day at 3AM. 19. Create a crontab entry that would run the file /etc/clear.sh every Wednesday at 5:01PM. 20. Create a command that will find all files under / that end in the extension *.txt, and whose contents contain either the word "new" or "old" or "borrowed" or "blue". (Look at egrep, watch the video!). CHECK YOUR WORK! (5 points).