Like you, students often ask me impossible questions. What is the length of an article? How long should I research it? How long will it take me to write? How long should I spend on editing? If you look through publications, you will see similar topics but of hugely varying lengths. Some have photos, some don't. Some have drawings, some don't. Some are on the front page, and most aren't. Your questions simply don't have neat answers. I always reply with the inscrutable questions-in-reply:
How long is piece of string?
How thick is it?
What colour is it?