Download Basic Probability

Simple & Compound Probability
Name: _______________________________
Directions: Use your former knowledge and intuition to answer the basic probability questions. There are
hints on the back if needed.
One of these names is to be drawn from a hat. Determine each probability below:
Mary
Jenny
Bob
Marilyn
Bill
Jack
Jerry
Tina
Connie
Joe
1. P(a 5-letter name that ends with an e) = ________________
(What is the probability of drawing a 5-letter name that ends with an e?)
2. P(4-letter name) = _____________
3. P(name starting with B) = ____________
4. P(name starting with J and 5-letter name) = ______________
5. P(name starting with J or a name ending with Y) = _____________
One card is drawn from a well-shuffled deck of 52 cards.
6. P(a black ace) = ________
7. P(a face card or a card with a prime number) = _________
8. P(a red 10 or a black 7) = ________
2
A spinner, numbered 1–8, is spun once. What is the probability of spinning…
1
3
8
4
7
5
6
9. P(NOT a diamond) = ______________
10. at least a 5? ___________
11. a prime number? _________
12. Suppose that the probability of snow is 0.58. What is the probability that it will
NOT snow? ________________
Hints:
If A and B are mutually exclusive events, then P(A or B) = P(A) + P(B).
and
If A and B are inclusive events, then P(A or B) = P(A) + P(B) – P(A B).
Apply the probability skills from above
13. A weather forecaster states that the probability of rain is 3/5, the probability of
lightning is 2/5, and the probability of both is 1/5. What is the probability of a sporting
event being cancelled due to rain or lightning?
14. A bag contains cards numbered from 1 to 14. One card is drawn at random. Find the
probability of selecting an 8 or a number less than 8.
15. Find the probability of selecting a boy or a blond-haired person from 12 girls, 5 of whom
have blond hair, and 15 boys, 6 of whom have blond hair.