Question

A door alarm works in 72 out of 100 cases and surveillance camera works in 68 out of 100 cases. what is the probability of effective screening techniques keeping in mind that these two methods can be used together?

Answer 1

Since these two methods can be used together, we can classify this into mutually inclusive events.

The probability for mutually inclusive events say A and B is:

P(A and B) =P(A) × P(B)

72/100 × 68/100=306/625

Answer 2

Answer:

The probability of effective screening technique is 0.4896.

Step-by-step explanation:

Let there be two events:

Door alarm works = Event A

Surveillance camera works = Event B

Therefore the Probability of two events is given as  P(A ∩ B) .

Now the two independent events are A and B.

Because, the happening of Event A is not related to B. and  

Similarly, the happening of Event B is not related to Event A.

The surveillance camera and door alarm work independently.

So we can write:

P(A ∩ B) = P(A) x P(B)

                              = 0.72 x 0.68

                               = 0.4896

Therefore the probability is 0.4896.