SOLUTION: Before electronics took over, slot machines were like this: you pull the lever to spin three wheels; each wheel has 20 symbols, all equally likely to show when the wheel stops spin

Algebra ->  Probability-and-statistics -> SOLUTION: Before electronics took over, slot machines were like this: you pull the lever to spin three wheels; each wheel has 20 symbols, all equally likely to show when the wheel stops spin      Log On


   



Question 432702: Before electronics took over, slot machines were like this: you pull the lever to spin three wheels; each wheel has 20 symbols, all equally likely to show when the wheel stops spinning; the three wheels are independent of each other. Suppose that the middle wheel has 9 cherries among its 20 symbols, and the left and right wheels have 1 cherry each.
a.) You win the jackpot if all three wheels show cherries. What is the probability of winning the jackpot?
b.)There are three ways that the three wheels can show two cherries and one symbol other than a cherry. Find the probability of each of these ways.
c.) What is the probability that the wheels stop with exactly two cherries showing among them?

Answer by edjones(8007) About Me  (Show Source):
You can put this solution on YOUR website!
a) 1/20 * 9/20 * 1/20 = 9/8000
.
c)
1/20 * 9/20 * 19/20 * 2 = 342/8000
(1/20)^2 * 11/20 = 11/8000
342/8000 + 11/8000 = 353/8000
.
Ed