Recent content by jackbauer

Hi people, I need some help with these questions please: 1.Is the set of all x in the real numbers such that (x+pi) is rational, countable? I don't think this is countable, isn't the only possible value for x = -pi, all other irrationals will not make x+pi rational i thought? 2.Is...

Hi people, could someone please help with the following: If a particle moves in a plane, and I've found that x.n=k where n=w/|w|, then how do i go about showing that the particle moves in a circle? A fly moves with constant speed v along the spoke of a wheel rotating with angular speed w...

Hi people, I was wondering if anyone could give me a hint with this problem. A RV X has PGF Gx(s)= (4-s)/3(4-3s) I need to get the P(X=i) from here. I know i can manipulate the above to get the sum to infinity of a geometric series, but i end up with the term (4-s) still in the P(X=i)...

Hi people, was wondering if someone could help me with this question. n men and m women are seated at a round table with n+m chairs. find the probability that a man amongst the n men has a woman seated immediately to his right? Find also the probability that a woman in the m women has a man...

Hi people, was wondering if anyone could help me with this problem. n men and m women are seated at a round table with exactly n+m places. What is the probability any given man has a woman immediately to his right. Also, what is the probability that a woman has a man to either side of her? I...

Hi people, could anyone tell me how to prove that the limit as f(x) approaches a from above equals the limit as f(x) approaches a from below? I can't see how to approach this proof, thx Jack

Hi people. I have a short question from a homework. given a family with 3 children, the sexes of which are unknown: if the eldest child is a boy and there is at least one other boy, then what is the probability one child is a girl? To me it seems obvious that there are at least...

Thanks for all the suggestions guys, could i just ask what is the simpler way of expressing nCr matt? Thanks

I have to prove that for 0<=k<=n that nCk(n choose k) is a natural number. I try by induction but i end up with n-m/m+1 must be a natural number which i don't know how to prove, is there another way besides induction? Could someone help me out? Thanks, Jack

Hi ppl, was hoping someone could point me in the right direction with this problem. 12 cards are dealt from a standard 52 pack of playing cards, 6 are kept face down, the others are 2 kings, two 3s, a 7 and a jack. Calculate the probability the 13th card drawn is a 2,3 or a 4. Could someone...