1. One card is drawn from a pack of 52 cards, each of the 52 cards being equally likely to be drawn. Find the probability that the card drawn is either red or king.
a. 1/4
b. 7/13
c. 15/26
d. 8/13
EXPLANATION
Red possibility = 26
King possibility (After eliminating red cards) = 2
Total = 26+2 = 28
Possibility = 28 / 52 = 7/13
2. Six dice are thrown simultaneously. Find the probability that all of them show the same face.
a. 1/6
b. 1/66
c. 1/36
d. 1/65
EXPLANATION
Total = 66
Possibility = 6/66 = 1/65
3. If you have 3 tickets to a lottery for which 10 tickets were sold and 5 prizes are to be given, the probability that you will win at least one prize is
a. 11/12 ⁄
b. 3/10
c. 1/2
d. 3/50
EXPLANATION
Total number of ways to select 5 tickets out of 10 tickets = 10C5
Total number of ways to select 5 tickets out of 7 remaining tickets (after selecting your 3 tickets) = 7C5
Probability of winning at least one prize = 1 – Probability of not winning any prize
Probability of not winning any prize = (number of ways to select 5 tickets out of 7 remaining tickets) / (number of ways to select 5 tickets out of 10 tickets) = 7C5 / 10C5 = (7*6) / (5*4) = 21/50
Therefore, Probability of winning at least one prize = 1 – 21/50 = 29/50 = 11/12
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