A small company uses three computers to trade on the New York Stock Exchange (NY
ID: 3043896 • Letter: A
Question
A small company uses three computers to trade on the New York Stock Exchange (NYSE). The chance of a computer failing in a day is 0.8%, and the computers fail independently. Computers are repaired in the evening, and each day is an independent trial. Let us define two events as follows: A: a specific computer fails on a dayB: all three computers fail on the same day
1. What is the probability of event A occurs within a year?
2. What is the probability of event B occurs within a year?
3. What is the mean number of days until a specific computer fails?
4. What is the mean number of days until all three computers fail on the same day?
Explanation / Answer
We are given that Probability of computer failing in a day is 0.8%,
1) probability of event A occurs within a year = 0.008
2) probability of event B occurs within a year = P( all failes) = (0.008^3) = 0.000000512