In a hand at whist, the specified players have 13 cards including fourkings.
Four kings can be drawn out of four in 4C4 ways.
The remaining nine cards held by him can be drawn out of the remaining 48 cards in the pack in 48C9 ways.
The total number of ways in which four kings and nine other cards can be drawn is 4C4× 48C9.
Favourable number of cases = 4C4× 48C9
Also, exhaustive number of cases = 52C13
∴ Required probability =