Answer:
0.002991
Step-by-step explanation:
Let
User is legitimate one = E₁
User is fraudulent one = E₂
User originates calls from two metropolitan = A
Therefore, according to the question
P(E₁) = 1 - 0.01% = 1 - 0.0001 = 0.9999
P(E₂) = 0.0001
P(A/E₁) = 1% = 0.01
P(A/E₂) = 30% = 0.30
Now,
P(E₂/A) =
or
P(E₂/A) =
or
P(E₂/A) = 0.002991
Answer: B) 5040
Step-by-step explanation:
Since total number of digits are 10 ( which are 0, 1, 2, 3, 4, 5, 6, 7, 8, 9)
And, According to the question, website requires a four-digit numerical password in which the digits cannot repeat.
Therefore, required possible arrangement =
=
=
=
= 10 × 9 × 8 × 7 = 5040
Thus, The required possible password is 5040.