Question

The probability that a civil servant own a car is 1/6,if two civil servants are selected at random.find the probability that

Answer 1

Answer:

The data we have is:

the probability that a civil servant own a car is 1/6

Two civil servants are selected at random.

a) The probability that each own a car.

Ok, here we have two events:

Person 1 haves a car.

Person 2 haves a car.

The probability of each of those events is the same, 1/6.

P1 = 1/6

P2 = 1/6

Now, the probability of both events happening at the same time is equal to the product of the individual probabilities.

P = P1*P2 = (1/6)*(1/6) = 1/36.

b) Only one has a car.

Suppose that Person 1 has the car and Person 2 has not a car.

The probability for person 1 is 1/6.

And for person 2, is the negation of having a car:

So if we have prob of having a car = 1/6

Then the probability of not having a car is = 1 - 1/6 = 5/6.

Then we have:

P1 = 1/6

P2 = 5/6.

The joint probability is:

P = P1*P2 = (1/6)*(5/6) = 5/36.

But we also have the case where person 1 does not have a car, and person 2 does have one, then we have a permutation, and the actual probability is two times the obtained above.

P = 2*(5/36) = 10/36