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.

New worksheetPractise online with hints

For teachers: free to print, copy and use in class. Every new worksheet has new values and its own answer key. A link to ExamProblems on your course page is appreciated.

Name: ____________________   Date: ____________

1.Easy
sum = 10die 1die 2112345672234567833456789445678910556789101166789101112P = ?

Two fair dice are rolled. What is the probability P that the sum is exactly 10?

2 dice= 10
P =
2.Easy
xp(x)1?20.3530.140.2

The table gives the probability distribution of X, but one probability is missing. Find P(X = 1).

x: 1, 2, 3, 4p(x): ?, 0.35, 0.1, 0.2
P(X = 1) =
3.Medium
red: 3blue: 4

A bag holds 3 red and 4 blue balls. You draw two balls without putting the first one back. What is the probability P that both are red?

3 / 4
P =
4.Medium
xp(x)10.120.330.3540.25μ = 2.75

For the distribution shown, find the variance Var(X) of X.

x: 1, 2, 3, 4p(x): 0.1, 0.3, 0.35, 0.25
Var(X) =
5.Hard
n = 6, p = 0.4: P(X ≤ 1) = ?k0123456

6 components are tested, and each one fails with probability 0.4, independently. What is the probability P that at most one fails?

n = 6p = 0.4
P =
6.Hard
n = 10, p = 0.25: P(X ≤ 1) = ?k012345678910

10 components are tested, and each one fails with probability 0.25, independently. What is the probability P that at most one fails?

n = 10p = 0.25
P =

Answer key

  1. 1. P = 0.08333
  2. 2. P(X = 1) = 0.35
  3. 3. P = 0.1429
  4. 4. Var(X) = 0.8875
  5. 5. P = 0.2333
  6. 6. P = 0.244

Full step-by-step solutions: practise this topic on examproblems.com.