If I get 1000 robux a month and get an additional 880 twice a month, how many months would it take to get 47000?

In a month, you would get 1000 robux + 880 robux + 880 robux = 2760 robux.

To get 47,000 robux, you would need to divide 47,000 by 2760 to get approximately 17.03 months.
Therefore, it would take about 17 months to get 47,000 robux.

impatient much?

Once is enough, thank you.
Repeated postings will not get faster or better responses.