Please help me....
Example:
I need to make 1 = $50 and 2 = $100 and 3 = $120 etc
I need to do this by entering 1, 2 or 3 in column A and the value
automatically appearing in column D, is this possible?

Also I would like to hide a column and only show cells from that column in
the row that I apply value to in another cell of the same row. Essentially
hiding the whole column and only showing value in a row when the row is in
use.

Please help me, I want to create something for a job interview and can't
work it out!

Thank you so much whoever can answer this.