A maybe 1, 2, 3, 4 times.
If b is 2p = C42/C53 *1/3+C43/C53 = 3/5.
A is 2,3,4 p =1-0.2 = 0.8.
P 1= 12/25
If b is 3 P=C42/C53*2/3=2/5.
A is 3,4 p =1-0.4 = 0.6.
P2=6/25
P=P 1+P2= 18/25