Odds question...anyone know...

Used to be 16s don't know if it's changed over the years.

16's??
Surely not..
Not to flop a set...any random pair

If you mean the board pairing on the flop, then it must be roughly 3 x (3/50 + 3/49), because each card on the table has 2 go's at finding it's pair. So that's about a 36% chance isn't it? Apologies if I have thought it out wrong.