A normal deck has 52 cards.
Our the deck has 4 cards less, 7 of clubs, 9 of hearts, 10 of spades, and 10 of hearts, so it has 48 cards.
To win the game, the card must be J, Q or K, so there are 12 cards available to win the game, so the probability is:

The probability (or chance) to win the hand is 25% (1/4).