Question

About 9% of the population of a large country is hopelessly romantic. If two people are randomly selected, what is the probability both are hopelessly romantic? What is the probability that at least one is hopelessly romantic?

A) The probability that both will be hopelessly romantic is _________. (Round 4 decimal places as needed).
B) The probability that at least one person is hopelessly romantic is _______.

Answer 1

0.1719

Explanation:

I just took the test and this was the correct answer. Sorry they did not offer an explanation and I still can not figure it out.

Answer 2

A. 0.0081

B. 0.1638

Explanation:

From the question, we are told that 9% of the population are hopelessly romantic.

The percentage that are not hopelessly romantic = 100-9 = 91%

The probability of choosing a hopelessly romantic person = 9% = 9/100 = 0.09

The probability of choosing a person who is not hopelessly romantic = 91% = 91/100 = 0.91

Now, we want to select two people and calculate the following probability;

1. Both will be hopelessly romantic

Let’s have the people as A and B

The probability that both will be hopelessly romantic will the the product of being hopelessly romantic probability = 0.09 * 0.09 = 0.0081

b. Probability that at least one person is hopelessly romantic

What this means is that the probability that one of the two ONLY is hopelessly romantic;

We can have two cases here;

Probability (That A is hopelessly while B is not )or Probability (A is not and B is hopeless )

Thus we have :

(0.09 * 0.91) + (0.91 * 0.09) = 0.0819 * 2 = 0.1638