You and opponent have the same hole card. Probability?

[Mr biggums]

Say you hold a king at a 10 person table. What is the probability that your opponent also has a king.

Say you hold k4 what is the probability that your opponent has k5 or higher?
K3 or K2?

Thank you

[js13_tps]

Wed. night in our weekly home game when we finally went heads up, on back to back hands myself and the other player were both dealt 99 on one hand, and AQo the next. Of course went all in both time and neither of us made a flush. Was pretty neat i thought, after that we chopped the pot for $100 each and watched the rest of the ballgame.

[scandal]

[ QUOTE ]
Say you hold a king at a 10 person table. What is the probability that your opponent also has a king.


[/ QUOTE ]

I'm not sure exactly which case you are asking about (preflop? flop?), but if you hold one K in the hole, and there is one K on the flop, there is a 37.5% chance that no other opponent in a 10-handed game has a K in the hole.