Question

A person trying to gain access to a bank vault must pass through a series of three security doors. If an attempt to pass through a door is a failure, then the person will not make any further attempts. Let P denote a successful pass and F denote a failed pass.
1. What is the sample space for this random experiment?
A) S ={PPP, FPP, PFP, PPF, FFP, FPF, PFF, FFF}B) S = {P, PP, PPP}C) S = {F, PF, PPF, PPP}D) S = {F, FP, FFP, FFF}E) S= {F, PF, PPF}

Answer 1

Answer:

C) S = {F, PF, PPF, PPP}

Step-by-step explanation:

For this case, we know that a person is trying to gain access to a bank vault and needs to go through 3 security doors, and we know that if the person does not pass a door, then he/she has no other attempts. We denote P= Successful pass , F= Failed pass

And we are interested on the sample space, we need to remember that the sample is the set with all the possible values for an experiment.

For this case the person can fail at the 1,2 or 3 try

For the case that fails at the 1 try we have F

For the case that fails at the 2 try we have PF

For the case that fails at the 3 try we have PPF

And the last option is that the person not fails at any try and we have PPP

So then the sample space would be given by:

C) S = {F, PF, PPF, PPP}