Wat is the difference between primary storage, secondary storage, and off-line storage

When you type the pwd command, you notice that your current location on the linux filesystem is the /usr/local directory. answer the following questions, assuming that your current directory is /usr/local for each question. a. which command could you use to change to the /usr directory using an absolute pathname? b. which command could you use to change to the /usr directory using a relative pathname? c. which command could you use to change to the /usr/local/share/info directory using an absolute pathname? d. which command could you use to change to the /usr/local/share/info directory using a relative pathname? e. which command could you use to change to the /etc directory using an absolute pathname? f. which command could you use to change to the /etc directory using a relative pathname?

When is a chart legend used a. all the time b. whenever you are comparing data that is the same c. whenever you are comparing multiple sets of data d. only for hand-drawn charts

Whats three fourths of 15(this is supposed to be in math but i clicked too fast)