Probability worksheet with answers

Free printable Probability worksheet: 6 problems from easy to exam level, with an answer key. Print it or save it as a PDF.

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Name: ____________________   Date: ____________

1.Easy
red: 7blue: 7green: 5

A bag holds 7 red, 7 blue and 5 green balls. You draw one at random. What is the probability P that it is blue?

7 / 7 / 5
P =
2.Easy
sum ≥ 4die 1die 2112345672234567833456789445678910556789101166789101112P = ?

Two fair dice are rolled. What is the probability P that the sum is at least 4?

2 dice≥ 4
P =
3.Medium
xp(x)10.2520.230.240.35μ = 2.65

For the distribution shown, find the standard deviation σ of X.

x: 1, 2, 3, 4p(x): 0.25, 0.2, 0.2, 0.35
σ =
4.Medium
red: 8blue: 3

A bag holds 8 red and 3 blue balls. You draw two balls without putting the first one back. What is the probability P that both are red?

8 / 3
P =
5.Hard
n = 10, p = 0.3: P(X = 5) = ?k012345678910

A test has 10 multiple-choice questions. A student who guesses gets each one right with probability 0.3, independently. What is the probability P of exactly 5 correct answers?

n = 10p = 0.3k = 5
P =
6.Hard
n = 6, p = 0.5: P(X = 1) = ?k0123456

A test has 6 multiple-choice questions. A student who guesses gets each one right with probability 0.5, independently. What is the probability P of exactly 1 correct answers?

n = 6p = 0.5k = 1
P =

Answer key

  1. 1. P = 0.3684
  2. 2. P = 0.9167
  3. 3. σ = 1.195
  4. 4. P = 0.5091
  5. 5. P = 0.1029
  6. 6. P = 0.09375

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