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: 2blue: 2

A bag holds 2 red and 2 blue balls. You draw one at random. What is the probability P that it is blue?

2 / 2
P =
2.Easy
red: 4blue: 4green: 3

A bag holds 4 red, 4 blue and 3 green balls. You draw one at random. What is the probability P that it is not red?

4 / 4 / 3
P =
3.Medium
xp(x)00.310.3520.35μ = 1.05

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

x: 0, 1, 2p(x): 0.3, 0.35, 0.35
σ =
4.Medium
n = 6k = 2N = ?

In how many ways N can a committee of 2 people be chosen from a group of 6? The order does not matter.

n = 6k = 2
N =
5.Hard
n = 11, p = 0.4: P(X ≤ 1) = ?k01234567891011

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

n = 11p = 0.4
P =
6.Hard
n = 10, p = 0.2: P(X = 3) = ?k012345678910

A test has 10 multiple-choice questions. A student who guesses gets each one right with probability 0.2, independently. What is the probability P of exactly 3 correct answers?

n = 10p = 0.2k = 3
P =

Answer key

  1. 1. P = 0.5
  2. 2. P = 0.6364
  3. 3. σ = 0.8047
  4. 4. N = 15
  5. 5. P = 0.03023
  6. 6. P = 0.2013

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