25% of the time there is free breakfast at work. You just woke up and are really hungry, so you call your coworker who is already at work, and he tells you there is free breakfast. However, he lies to you 1/3 of the time. How likely is it that there is free breakfast at work today?

Respuesta :

Answer:

[tex]\frac{1}{6}[/tex]

Step-by-step explanation:

Data provided in the question:

Probability of free breakfast = 25% = 0.25

P( coworker lies | free breakfast ) = [tex]\frac{1}{3}[/tex]

Therefore,

P(Coworker did not lie | Free Breakfast)

= 1 -  P( coworker lies | free breakfast )

= 1 -  [tex]\frac{1}{3}[/tex]

=  [tex]\frac{2}{3}[/tex]

Now,

P(Free breakfast at work | coworker told there is free breakfast)

=  P(Coworker did not lie | Free Breakfast) × P(Free breakfast)

= [tex]\frac{2}{3}[/tex] × 0.25

= [tex]\frac{1}{6}[/tex]

The likelihood that there is free breakfast at work today is from the given scenarios is; 40%

How to solve probability?

Let X be the chance that both there is breakfast and your friend tells you there is breakfast.

Let Y be the chance that your friend tells you there is breakfast on any given day.

We are told that on any given day, there is 1/4 chance of breakfast and 2/3 chance of your friend telling the truth.  

There are are a total of 12 possibities but the breakdown of the likely ones are;

  • Breakfast (2/3 times, he will tell you there is Breakfast and there is)

  • No Breakfast (1/3 times, he will tell you there is Breakfast and there is not)

  • No Breakfast (1/3 times, he will tell you there is Breakfast and there is not)

  • No Breakfast (1/3 times, he will tell you there is Breakfast and there is not)

We can say that there is a 5/12 chance that, on any given day, your friend will tell you there is breakfast. Thus; Y = 5/12

Amongst the 12 possible scenarios we see that there was both Breakfast plus  your friend telling you there is breakfast twice. Thus;

X = 2/12

Thus;

The likelihood that there is free breakfast at work today is;

X/Y = (2/12)/(5/12) = 2/5 = 40%

Read more about probability at; https://brainly.com/question/25870256