Sorry, meant 12, not 1.2.
And therein is the problem, some folks are getting what my son things the answer is and some are getting what I think the answer is.
The conflict continues, LOL.
If, as stated, each antellope averages five offspring over a ten year lifetime, the population of antellopes cannot possibly be stable at 24,000 (or any number). Rather, the population would increase fivefold every ten years, ten-million-fold per century, and by a factor of almost 10^70 over the course of a millenium.