In a raffle in which 200 tickets are sold, there are 3 prizes - first prize of $100, second prize of $50, third prize of $30. A girl has one ticket in the raffle. What is the probability that she wins
(a) a prize,
(b) at least $50.
I really suck at Probaility and counting. But here's my try.
1) Atleast a prize:
P(First) = 1/200 (she has one ticket, hence the probability of her winning the prize is 1 in 200)
P (Second) = 199/200 * 1/199 (Probability of not winning first * Probability that she wins 2nd)
P(third) = 199 / 200 * 198/199 * 1/198 (Prob of not winnning first and second * prob of winning third)
P (at least one) = P(First) + P(second) + P(Third)
2) Winning 3rd - P(Third) from above.
Am I right?