Linux files and directories quiz

Twelve questions across the whole chapter. Each answer explains why. Aim for nine before moving on to chapter 4.

Which directory holds data that grows while the system runs and must survive a reboot, such as logs and databases?
Which of these is an absolute path?
You are in /etc/ssh. Where does cd ../../var take you?
Which command lists the hidden files in your home directory as well as the others?
backup is an existing directory. What does mv config.yml backup do?
Which command copies the directory site, with everything in it, to site-old?
You run rmdir build and get "Directory not empty". What does that tell you?
How many hard links does a file have if ls -l shows a link count of 1?
Which can a symbolic link do that a hard link cannot?
current is a symbolic link to the directory release/v1. Which command repoints it to release/v2?
What does touch log-{mon,tue,wed}.txt create?
Which line prints "Cost: $5 per user" exactly?