Answer:
$ 9.22
Explanation:
1st cost = $0.15 and p is unknown
2nd cost = $1.15 and Probability of 0.3
3rd cost = $0.74 and Probbility of 0.45
1st prize value variable is = p
to gain $1 on each ticket the gain for the ticket purchaser must be $-1
we have that the probabilities of winning add to 0.9 so, the probability of losing $3 is 0.1
formula:
Probability of winning:
W(p) = 0.15p + 0.3*1.15 + 0.45*0.74 - 3*0.1 = -1
0.15p + 0.3825 = -1
0.15p = - 1.3825
p = - 9.2166
p = -9.22
The 1st prize must be $ 9.22