Question 1164737
.
A trading company has eight computers that it uses to trade on the New York Stock Exchange
(NYSE). The probability of a computer failing in a day is 0.005, and the computers fail
independently. Computers are repaired in the evening and each day is an independent trial.
(a) What is the probability that all eight computers fail in a day?
(b) What is the mean number of days until a specific computer fails?
(c) What is the mean number of days until all eight computers fail in the same day
compute the solution in R ?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


<pre>
(a)  What is the probability that all eight computers fail in a day?


     This probability is  P = {{{0.005^8}}} = 3.90625E-19.    <U>ANSWER</U>

     Interesting to note that this number is a PRECISE value - not an approximate !



(b)  What is the mean number of days until a specific computer fails?


     The mean number of days until a specific computer fails is  

        {{{1/0.005}}} = 200 days.    <U>ANSWER</U>



(c) What is the mean number of days until all eight computers fail in the same day


     The mean number of days until all eight computers fail in the same day is  

         {{{1/3.90625E-19}}} = 2.56E+18 = {{{2^8*10^16}}} days.    <U>ANSWER</U>


      According to the current knowledge, our Universe exists about 13.8 billion years,
      which is less than the answer to this question.
</pre>

Solved.  All questions are answered.