The missing part in the question;
and the payoff is $2.20 won for every dollar bet. (As the player’s probability of winning in this case is 
........
Also:
For such a bet, the casino pays off as shown in the following table.
The table can be shown as:
Keno Payoffs in 10 Number bets
Number of matches Dollars won for each $1 bet
0 - 4 -1
5 1
6 17
7 179
8 1299
9 2599
10 24999
Answer:
Step-by-step explanation:
Given that:
Twenty numbers are selected at random by the casino from the set of numbers 1 through 80
A player can select from 1 to 15 numbers; a win occurs if some fraction of the player’s chosen subset matches any of the 20 numbers drawn by the house
Let assume X to represent the numbers of player chooses which are in the Casino-selected-set of 20.
Let assume the random variable X has a hypergeometric distribution with parameters N= 80 and m =20.
Then, the probability mass function of a hypergeometric distribution can be defined as:
Now; the probability that i out of n numbers chosen by the player among 20 can be expressed as:
Also; given that ; When the player selects 2 numbers, a payoff (of odds) of $12 won for every $1 bet is made when both numbers are among the 20
So; n= 2; k= 2
Then :
Probability P ( Both number in the set 20) 
Probability P ( Both number in the set 20) 
Probability P ( Both number in the set 20) 
Probability P ( Both number in the set 20) 
Thus; the payoff odd for is 16.63:1 ,as such fair payoff in this case is $16.63
Again;
Let assume X to represent the numbers of player chooses which are in the Casino-selected-set of 20.
Let assume the random variable X has a hypergeometric distribution with parameters N= 80 and m =20.
The probability mass function of the hypergeometric distribution can be defined as :
Now; the probability that i out of n numbers chosen by the player among 20 can be expressed as:
From the table able ; the expected payoff can be computed as shown in the attached diagram below. Thanks.
