Quote:
Originally Posted by captain dean
For the life of me I can't figure out how to solve this and I am in "dire" need of the answer.
"An object randomly changes between five different colors once a day. A person randomly guesses the objects color twice a day (not the same guess in one day). What are the chances that the person WON"T guess the objects color after 22 days?"
I came up with .0061%
Please give me a hand.
I assume at least he knows what the five possible colors are, so he's not guessing aqua and chartreuse while the object switches between green red blue orange and purple. Absurd problem otherwise. So, the object changes color each day and stays the same color throughout the day, it might be blue on day 1 then red on day 2, etc? Seems like the hard part here is understanding what the problem is. Could be stated more clearly but I think I understand.
Ok so he makes two (different) guesses per day, meaning on any given day 2/5 chance of guessing the correct color for the day. But you want the probability he guesses incorrectly for 22 days straight. On any given day he has a 3/5 chance of not guessing correctly, so 22 straight days of never guessing right is (3/5)^22 = .00001316.