Winning at KENO: Calculating the Expected Value (E(n))

[sam_0017]

game of KENO ?

can anyone help whit this question ?

[PLAIN]http://up.arab-x.com/Oct11/doY59204.png


E(n) = Ʃ p(n) × a(n)
" represent the probability you get i matches as P(i), the amount you win for i
matches as A(i) and the expected value for n numbers picked as E(n)."

 

[vrmuth]

can anyone help whit this question ?

E(n) = Ʃ p(n) × a(n)
" represent the probability you get i matches as P(i), the amount you win for i
matches as A(i) and the expected value for n numbers picked as E(n)."

E(40)? what's a(20) , a(21), etc. ? also i think the question is not complete , given data is not sufficient (for eg. with what (and how many ) numbers the chosen numbers are matched )

 

[dynamicsolo]

I'm assuming for the moment that you know how to calculate the probabilities for the numbers of matches. I suspect what the author is calling "E(40)" is the expected value of your winnings for this 40-choice version of the game, not the probability of up to 40 matches (which happens only a little sooner than the heat-death of the Universe... ;) ). Is it the case that the other problem (which I'm guessing is related to basic Keno) asks for "E(20)" ?