Integers a, b, c, and d, not necessarily distinct, are chosen independently and at random from 0 to 2007, inclusive. What is the probability that ad-bc is even?
Jack rolls 5 fair six-sided dice. What is the probability that at least two dice show the same number?
The probability of getting rain on any given day in June in Capital City is 1/10. What is the probability that it rains on at most 2 days in June? Express your answer as a decimal to the nearest thousandth.
Carson flips over the cards of a standard 52-card deck one at a time. What is the probability that he flips over the ace of spades before any face card (jack, queen or king)?
The probability of getting rain on any given day in June in Capital City is 1/10. What is the probability that it rains on at most 2 days in June? Express your answer as a decimal to the nearest thousandth.
P ( rain 0 days ) = (.9)^30
P (rain 1 day ) = C(30, 1)(.1)(.9)^29
P(rain on 2 days) = C(30, 2) (.1)^2 (.9)^28
So...P(rain at most 2 days ) =
(.9)^30 + C(30, 1)(.1)(.9)^29 + C(30, 2) (.1)^2 (.9)^28 ≈ .4114
Jack rolls 5 fair six-sided dice. What is the probability that at least two dice show the same number?
1st die - any number, or.................................................................. = 6/6
2nd die-probability that it is different from the first...................... =5/6
3rd die-................................................................................1st two =4/6
4th die-...............................................................................1st three =3/6
5th die-................................................................................1st four =2/6
So, the probability that they are all different from each other =6/6 x 5/6 x 4/6 x 3/6 x 2/6 =6! / 6^5 =0.09259.
And the probability that at least 2 of them show the same number =1 - 0.09259 =90.74%