Norm66 said:
With only two the odds of getting two males, two females, or a m/f pair are even which makes the odds of getting a m/f pair only one in three. So yea, it's possible you have two males or two females.
You covered m/m, f/f, and m/f, but you left out f/m. The odds of having one male and one female is 50/50.
Still not odds I'd bet on
-Rick (the armchair aquarist)
P.S. If you assume that each fish has a 50/50 chance of being male or female, here are the odds of getting at least one of each in a batch of fish :
# fish - odds of at least one fish of each sex
1 -- 0%
2 -- 50%
3 -- 75%
4 -- 87.5%
5 -- 93.75%
6 -- 96.875%
P.P.S. Just because you have a male and a female doesn't 100% guarantee that they will be mates. I suspect that in many (most?) cases, though, the urge to reproduce will kick in and she'll eventually take the only available male