Set z ... to draw the bank card.

Suppose it's j ... draw a bank card.

Suppose n ... draws ABC card.

Suppose it's g ... draw the ICBC card.

rule

P(Z)= 1/3，

P(J)+P(N)=5/ 12

P(G)+P(N)=5/ 12

P(Z)+P(J)+P(G)+P(N)= 1

solve

P(J)=P(G)= 1/4

P(N)= 1/6

Solution 2:

The probability of getting BOC cards is 1/3, indicating that the number of BOC cards is 4.

The probability of obtaining CCB card or ABC card is 5/ 12, indicating that the number of CCB cards+ABC cards =5.

The probability of getting an ABC card or an ICBC card is 5/ 12, indicating that the number of ICBC cards+the number of ABC cards =5.

Number of BOC cards+CCB cards+ABC cards+ICBC cards = 12.

Solution: CCB card number = ICBC card number =3, ABC card number =2.

The probability of obtaining CCB card, ABC card and ICBC card is 1/4, 1/6 and 1/4 respectively.