So the difference here is in meaning.EXAMPLE #1:
"We have lived in a hut for 3 days"
MEANING: Some time in the past, we lived in the hut for 3 days. It could have been 10 yrs ago, this past year, or 3 days ago. There's no specified time. All we know is it happened in the past at some point.EXAMPLE #2:
"We have been living in a hut for 3 days"MEANING:
This means that starting from 3 days ago, we have been living in the hut and that continues to the present day. So this example, is a lot more specific about the time period we talk about - extending into the present.Both can work - just slightly different meanings.
Check out our SC Pill
for more complex grammar stuff broken down into really easy-to-understand frameworks!
... and more
What's Inside GMAT Pill?
Zeke Lee, GMAT Pill Study Method (Study Less. Score More.)
GMAT Pill Reviews | GMAT PILL Free Practice Test