$4\mathrm{.}1$ Linux file permission:$$ Is "documents" a file or a directory? What does the file permission for the following entry mean? $(6$pts$)$

drw$-$r$-----1$ jdoe$$ jdoe$0$ Mar $1110$:$54$ documents

$$

Q$4\mathrm{.}2$ Suppose you are a Linux systems administrator, and one of your user Jane Doe $($userid: jdoe$)$ has a resume file which cannot be displayed by the web server:

$$ jdoe$/$public$\_$html$>$ ls $-$al resume.html

$-$rw$-$r$-----1$ jdoe$$ jdoe$0$ Mar $1110$:$54$ resume.html

In order to fix this problem, you'll have to make the file "readable," for the rest of the world, e$.$g$.,$ the file permission should look like this:

$-$rw$-$r$--$r$--1$ jdoe$$ jdoe$0$ Mar $1110$:$54$ resume.html

What Linux command should you issue to make this change happen $($please include the Linux command, command switches$/$options$,$ and command arguments$)?(6$pts$)$

Q$4\mathrm{.}3$ Under Linux command prompt, when you type "umask," the result shows $"0021".$ Please explain what $"0021"$ means. $(8$ pts$)$