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
red: 6blue: 5green: 5

A bag holds 6 red, 5 blue and 5 green balls. You draw one at random. What is the probability P that it is blue?

6 / 5 / 5
P =
2.Easy
sum ≥ 7die 1die 2112345672234567833456789445678910556789101166789101112P = ?

Two fair dice are rolled. What is the probability P that the sum is at least 7?

2 dice≥ 7
P =
3.Medium
P(at least one six) = ??1?2?3?4?5?6P(six) = 1/6 on each roll

A fair die is rolled 6 times. What is the probability P of getting at least one six?

n = 6
P =
4.Medium
xp(x)100.25200.2300.2400.35μ = 26.5

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

x: 10, 20, 30, 40p(x): 0.25, 0.2, 0.2, 0.35
σ =
5.Hard
n = 11, p = 0.3: P(X ≤ 1) = ?k01234567891011

11 components are tested, and each one fails with probability 0.3, independently. What is the probability P that at most one fails?

n = 11p = 0.3
P =
6.Hard
n = 7, p = 0.7: P(X = 5) = ?k01234567

A test has 7 multiple-choice questions. A student who guesses gets each one right with probability 0.7, independently. What is the probability P of exactly 5 correct answers?

n = 7p = 0.7k = 5
P =

Answer key

  1. 1. P = 0.3125
  2. 2. P = 0.5833
  3. 3. P = 0.6651
  4. 4. σ = 11.95
  5. 5. P = 0.113
  6. 6. P = 0.3177

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