Name: _______________________ Date: __________________ Per.: _______
Theoretical Probability Practice
At a school fair, you have a choice of randomly picking a ball
from Basket A or Basket B. Basket A has 5 green balls, 3 red
balls, and 8 yellow balls. Basket B has 7 green balls, 4 red
balls, and 9 yellow balls. You can win a digital book reader
if you pick a red ball.
Basket A
Basket B
Total # of
Outcomes
# of Red
Balls
1) Complete the chart. Write each answer in simplest form.
P(win)
2) Which basket should you choose if you want the better chance
of winning?
3) Jim has 4 nickels, 6 pennies, 4 dimes, and 2 quarters in his pocket. He picks a coin at random. What is the
probability that he will pick a nickel or a dime? Write your answer as a fraction, as a decimal, and as a
percent.
4) A choir has 12 boys and 15 girls. The conductor randomly picks one child to lead the class in singing.
a. What is the probability the conductor picks a boy?
b. What is the probability the conductor picks a girl?
c. Describe two different ways you could find the answer to part (b).
Use the spinner for #5-8.
5) In 20 spins, about how often can you expect to land on an even number?
6) In 150 spins, about how often can you expect to land on a number less than 6?
7) In 200 spins, about how often can you expect to land on a 1?
8) Randy says there is a greater chance of landing on an even number than on
an odd number? What is his error?
Answer Key
1)
Total # of
Outcomes
# of Red
Balls
P(win)
Basket A
Basket B
16
20
3
4
3
16
1
5
2) Basket B
3)
1
; 0.5; 50%
2
4) a.
4
9
b.
5
9
c. You could find the complement of part (a) or find the theoretical probability of picking a girl.
5) 10
6) 94
7) 25
8) The chances of landing on an even number is
number.
1
, which is the same probability as landing on an odd
2