Option( c ) is the correct one.
-2x +y= -3
x= (3+y)/2
By executing the value in second equation
{-(3+y)/2} +2y =3
( -3-y +4y)/2 =3
-3 +3y =6
3y = 9
y = 3
Again by substituting the value of y in any of the equation
-2x +y =-3
-2x =-6
x= 3.

7 0

3 years ago

You are working in a primary care office. Flu season is starting. For the sake of public health, it is critical to diagnose peop

Aleksandr-060686 [28]

Answer:

E. 0.11

Step-by-step explanation:

We have these following probabilities:

A 10% probability that a person has the flu.

A 90% probability that a person does not have the flu, just a cold.

If a person has the flu, a 99% probability of having a runny nose.

If a person just has a cold, a 90% probability of having a runny nose.

This can be formulated as the following problem:

What is the probability of B happening, knowing that A has happened.

It can be calculated by the following formula

$P = \frac{P(B).P(A/B)}{P(A)}$

Where P(B) is the probability of B happening, P(A/B) is the probability of A happening knowing that B happened and P(A) is the probability of A happening.

In this problem, we have that:

What is the probability that a person has the flu, given that she has a runny nose?

P(B) is the probability that a person has the flu. So P(B) = 0.1.

P(A/B) is the probability that a person has a runny nose, given that she has the flu. So P(A/B) = 0.99.

P(A) is the probability that a person has a runny nose. It is 0.99 of 0.1 and 0.90 of 0.90. So

$P(A) = 0.99*0.1 + 0.9*0.9 = 0.909$