Probabilistic Reasoning Practice Questions

1. In a group of 100 people, 60 like coffee, 70 like tea, and 40 like both. What is the probability that a randomly selected person likes either coffee or tea?

0.6

0.7

0.8

0.9

2. A fair six-sided die is rolled seven times. What is the probability of getting at least one 3?

1 - (5/6)^7

1 - (4/6)^7

1 - (3/6)^7

1 - (2/6)^7

3. A fair six-sided die is rolled twice. What is the probability of getting a sum of 7?

1/6

5/36

1/4

7/36

4. If you draw two cards from a standard deck of 52 cards without replacement, what is the probability that both are aces?

1/221

1/169

1/121

1/91

5. If you randomly select a day of the week, what is the probability that it's a weekday (Monday to Friday)?

2/7

3/7

4/7

5/7

6. In a group of 100 people, 40% are male. If a person is selected at random, what is the probability that the person is female?

0.4

0.5

0.6

0.7

7. In a standard deck of 52 cards, what is the probability of drawing a king or a spade?

4/13

13/52

16/52

17/52

8. In a standard deck of 52 cards, what is the probability of drawing a red card or a picture card (Jack, Queen, or King)?

7/13

8/13

9/13

10/13

9. If you draw a card from a standard deck, replace it, and draw again, what is the probability of drawing two different suits?

1/4

1/2

3/4

13/17

10. A box contains 3 red balls, 4 blue balls, and 5 green balls. If you draw two balls with replacement, what is the probability that both balls are the same color?

1/3

25/144

41/144

1/2