Answer:
A) 0.9
B) 0.99
C) 0.999
D) Yes, i will recommend.
Step-by-step explanation:
We are given that p = 0.9
Now, the formula for the binomial probability is given as;
f(k) = (n,k) (p^(k)) [(1-p)^(n-k)]
Thus;
A) n = 1;
f(1) = (1,1) (0.9)¹ [(1-0.9)^(1-1)]
= 1 x 0.9 x 1 = 0.9
B) n=2;
f(1) = (2,1) (0.9)¹ [(1-0.9)^(2-1)] = 2 x 0.9 x 0.1¹ = 0.18
f(2) = (2,2) (0.9)² [(1-0.9)^(2-2)] = 0.81 x 1 = 0.81
Thus;
P(X ≥ 1) = f(1) + f(2) = 0.81 + 0.18 = 0.99
C) n = 3;
f(1) = (3,1) (0.9)¹ [(1-0.9)^(3-1)] = 3 x 0.9 x 0.1² = 0.027
f(2) = (3,2) (0.9)² [(1-0.9)^(3-2)] = 3 x 0.81 x 0.1 = 0.243
f(3) = (3,3) (0.9)³ [(1-0.9)^(3-3)] = 0.729 x 1 = 0.729
P(X ≥ 1) = f(1) + f(2) + f(3) = 0.027 + 0.243 + 0.729 = 0.999
D) Yes, i will recommend that multiple detection systems are used, because when three systems are used, then it is nearly impossible to not detect the attack.