Suppose you just received a shipment of eight televisions. Three of the televisions are defective. If two televisions are randomly​ selected, compute the probability that both televisions work. What is the probability at least one of the two televisions does not​ work?

Respuesta :

Answer: The probability that both televisions work is [tex]\dfrac{5}{14}.[/tex]

The probability at least one of the two televisions does not​ work is [tex]\dfrac{9}{14}[/tex].

Step-by-step explanation:

Given : Number of televisions received = 8

Number of defective televisions=3

Number of good television = 8-3=  5

Then , the number of ways to select any two television out of 8 = [tex]^8C_2[/tex]

The number of ways to select two working televisions out of three = [tex]^5C_2[/tex]

Now ,  If two televisions are randomly​ selected, the the probability that both televisions work

[tex]=\dfrac{^5C_2}{^8C_2}=\dfrac{\dfrac{5!}{2!3!}}{\dfrac{8!}{2!6!}}=\dfrac{\dfrac{5\times4\times3!}{2\times3!}}{\dfrac{8\times7\times6!}{2\times6!}}=\dfrac{5}{14}[/tex]

Hence, the probability that both televisions work is [tex]\dfrac{5}{14}.[/tex]

Also , the probability at least one of the two televisions does not​ work = 1- P( both televisions work)

[tex]=1-\dfrac{5}{14}=\dfrac{14-5}{14}\\\\=\dfrac{9}{14}[/tex]

Hence, the probability at least one of the two televisions does not​ work is [tex]\dfrac{9}{14}[/tex]

Answer:

A) 0.604

B) 0.396

Step-by-step explanation:

# of televisions = 14

# of defective televisions = 3

# of working televisions = 14 - 3 = 11

P(both televisions work) = 11/14 x 10/13 = 0.604

P(at least one of the two televisions does not work) = 1 - P(both televisions work)

1 - 0.604 = 0.396