Let's label the letters by "1","2",...,"n". I agree that it's easy to see that when you put your FIRST letter into an envelope, it correrctly...
Suppose we have "n" envelopes and "n" letters and we put letters to envelopes at random. Let I_i = I({i-th letter matches}) =1 if the i-th letter...
How about the coin??? By the way, is this a "birvariate" question? How can I define the second random variable?
1) Suppose we roll a fair die. Whatever number comes up, we toss a coin that many times. What is the probability mass function of the number of...
Thanks a lot! This really helps! So for question 2, P(exactly one head) = P(box B is chosen) = 1/2 and the FINAL answer is just P(exactly one...
1) At a party, 4 males decide to ask 4 females to dance. How many ways can 4 couples be formed, assuming that each male asks exactly one female to...
Thanks for helping! Valves | | | 1 2 3 | Probability | Paths | ----------+---------------+-------| 0 0 0 |...
I am a bit confused...what does B represent? Is it the probability? If so, wouldn't it be: signal | B (output) 0 0 0 | 0.2^3 ? 0 0 1 | 0.8 x...
I think the probability that both the top and bottom pipes will be fully open = 0.8^3 But I have some trouble with your two latter questions, how to...
Thanks, but do you have any idea what is going on with the "signal" that the problem talks about twice?
Consider a system of water flowing through valves from A to B as shown in the diagram. Valves 1, 2, and 3 operate independently, and each correctly...
2c) Is the answer 15/20 x 14/19 x 13/18 x 12/17 ??? How can I get the answer to part c using the approach (using factorials) as in parts a and b???
I don't quite get your point. But most definitely M x M x ... x M = M^n is assuming that order matters (permutation with replacement), and nCk at...
Sorry, I don't know tex and I am trying to keep the expressions simple. ^ means "to the exponent of"
1) A company orders supplies from M distributors and wishes to place n orders (n<M). Assume that the company places the orders in a manner that...
2c) I think the complement would be that "at least one ethnic group member is assigned to a type 4 job", wouldn't it be even more complicated then?
1) So is it true in general that when calculating a "probability", (order unimportant) / (order unimportant) and (order important) / (order...
1) In a lottery there are 10 tickets numbered 1,2,3,...,10. Two nubmers are drawn for prizes. You hold tickets 1 and 2. What is the probability that...
1) A balanced die is tosssed six times, and the number on the uppermost face is recorded each time. What is the probability that the numbers recorded...
Still wondering...
Separate names with a comma.
