Steven H. answered 08/03/20
Former teacher with 10yrs experience
- Let's start with the overall probability of hitting 0. Since the probability of black section is 1/4 each, then the overall probability of hitting 0 is 1/2. So if you spin twice, you could miss the black section on both, hit it on one spin, or hit it on both spins. To be efficient, let's calculate the chances of missing the black section on both and subtracting from 1 a.k.a inverse probability.
- Pr( at least once) = 1-Pr(never hitting black section) = 1-.5^2 = 0.75
- Pr(jackpot)*Pr(jackpot) = (1/60)*(1/60) = 1/3600
- Pr(respin and winning money) = Pr(respin)*Pr(winning money)
Pr(winning money) = Pr(yellow)+Pr(orange)+Pr(white) = 1/30 +1/30 +1/60= 1/12
Pr(respin and winning money) = 1/12 *1/12 = 1/144
4.Pr(blue and black) = Pr(blue)*Pr(black) = 1/8*1/2 = 1/16. Since the spins are independent of one another.
5.Pr(blue once and black once) = 1/16*2 = 1/8.
6. Question 4 takes order into account, question 5 doesn't. So in Q5 you have to account for blue coming first or black coming first. Since the probability is the same, you just need to double it.