Answer:
The PMF of B is given by
P(B=0) = 0.7
P(B=1) = 0.16
P(B=2) = 0.08
P(B=3) = 0.04
P(B=4) = 0.02
Step-by-step explanation:
Let x denote P(B=1), we know that
P(B=0) = 1-0.3 = 0.7
P(B=1) = x
P(B=2) = x/2
P(B=3) = x/4
P(B=4) = x/8
Also, the probabilities should sum 1, thus
0.7+x+x/2+x/4+x/8 = 1
15x/8 = 0.3
x = 0.16
As a result, the PMF of B is given by
P(B=0) = 0.7
P(B=1) = 0.16
P(B=2) = 0.08
P(B=3) = 0.04
P(B=4) = 0.02