Success TutoringWorksheets
WorksheetYear 12Level 3 · ChallengeHSCVCE

Free Year 12 The Binomial Distribution Worksheet

A senior maths worksheet on the binomial distribution: recognising Bernoulli trials and binomial situations, calculating P(X = k) with the binomial formula, cumulative and at least one probabilities, the mean np and variance np(1 − p), finding n and p from the mean and variance, and the smallest number of trials needed. Finishes with an extended seed germination problem. Full working is given for every answer.

Instant download · No sign-up · Free for personal, classroom and homeschool use

Year
Year 12
Subject
Maths
Topic
Statistics
Difficulty
Level 3 · Challenge
Estimated time
50 minutes
Curriculum
Australian Curriculum
Questions
16
Answers
Included, with working
Format
PDF (A4), print or complete online

Students will practise

  • identifying the conditions for a binomial distribution and the parameters n and p
  • calculating binomial probabilities with the binomial probability formula
  • using the complement for at least and at most probabilities
  • calculating and interpreting the mean, variance and standard deviation of a binomial random variable

Curriculum: Australian Curriculum. We show specific outcome codes only where they have been verified against the official curriculum document.

What's next?

Completed: The Binomial Distribution

  1. 1Continuous Random Variables and Probability Density Functions

How to use this worksheet

  1. Print the PDF or complete it on screen. Write the student's name and date at the top.
  2. Read the instructions for each part together before starting. Encourage working to be shown, not just answers.
  3. Mark with the answer sheet. Compare the method, not only the final answer, and give credit for correct working.
  4. Record the score, celebrate what went well, then follow the "What's next" suggestion.

Common questions

Who is this worksheet for?

Year 12 students (typically ages 17–18) working on statistics. It is pitched at level 3 · challenge.

Are the answers included?

Yes. The PDF includes a full answer sheet with the working for every question. You can also view the answers online.

How long does it take?

About 50 minutes for 16 questions. Short, regular sessions work best: two or three a week beats one long one.

Do I need to sign up to download?

No. Click Download Free PDF and it opens immediately. It is free for personal, classroom and homeschool use.

What should we do next?

Try Continuous Random Variables and Probability Density Functions.

Preview

Success TutoringWorksheetsYear 12 · Mathematics · Statistics

The Binomial Distribution

Name

Date

Score /

Show your working. Give probabilities correct to 4 decimal places unless they are exact.

Part A: Bernoulli trials and binomial situations

A Bernoulli trial has exactly two outcomes, success (probability p) and failure (probability 1 − p). For one trial, E(X) = p and Var(X) = p(1 − p).

X is binomial, written X ~ Bin(n, p), when it counts the successes in a fixed number n of independent Bernoulli trials, each with the same probability p of success.

Worked example. A basketball player makes 70% of free throws and takes 10 shots, independently. The number of shots made is X ~ Bin(10, 0.7). The number of shots taken until the first miss is not binomial, because n is not fixed.

1.Which situation can be modelled by a binomial distribution?
  1. AThe number of sixes when a fair die is rolled 12 times
  2. BThe number of rolls of a die needed to get the first six
  3. CThe total of the numbers shown when a die is rolled 12 times
  4. DThe time until the next customer arrives
2.Drawing 5 cards without replacement from a standard 52-card deck and counting the hearts gives a binomial distribution. ☐ True   ☐ False
3.A Bernoulli trial has probability of success p = 0.3. Find the mean and variance of the number of successes in one trial. (answer space)

Part B: Binomial probabilities

If X ~ Bin(n, p), then P(X = k) = [sup n]C[sup k] p[sup k] (1 − p)[sup n − k] for k = 0, 1, 2, …, n. The nCk counts the orders in which k successes can occur among the n trials.

For at least one, use the complement: P(X ≥ 1) = 1 − P(X = 0) = 1 − (1 − p)n. For at most k, add P(X = 0) up to P(X = k).

Worked example. A fair coin is tossed 4 times. P(exactly 3 heads) = 4C3 (0.5)3 (0.5)1 = 4 × = 0.25, and P(at least one head) = 1 − (0.5)4 = 1 − 0.0625 = 0.9375.

4.X ~ Bin(5, 0.5). Find P(X = 2).
5.X ~ Bin(10, 0.2). Find P(X = 3), correct to 4 decimal places.
6.X ~ Bin(6, 0.3). Find P(X = 0) and P(X ≥ 1), correct to 4 decimal places.
7.X ~ Bin(4, 0.6). Find P(X ≤ 1).
8.X ~ Bin(3, 0.4). Write the full probability distribution of X and check that the probabilities add to 1.
9.A multiple-choice quiz has 8 questions, each with 4 options. A student guesses every answer. Find, correct to 4 decimal places, (a) the probability of exactly 4 correct answers and (b) the probability of at least one correct answer.
10.A machine produces faulty items with probability 0.1, independently. What is the smallest number of items that must be checked for the probability of finding at least one faulty item to exceed 0.95?

Part C: Mean, variance and standard deviation

If X ~ Bin(n, p), then E(X) = np, Var(X) = np(1 − p) and SD(X) = √(np(1 − p)). The mean is the long-run average number of successes in n trials.

Worked example. A fair die is rolled 30 times and X is the number of sixes. E(X) = 30 × = 5, Var(X) = 30 × × = ≈ 4.17 and SD ≈ 2.04.

11.X ~ Bin(20, 0.15). Find the mean, the variance and the standard deviation of X (standard deviation to 2 decimal places).
12.A binomial random variable has mean 6 and variance 4.2. Find n and p.
Free worksheets at worksheets.successtutoring.com · © Success Tutoring · Free for personal and classroom use

Preview — the PDF contains the full resource and answer sheet.

  • Study Guide

    Bivariate Data: Correlation and Lines of Best Fit

    An HSC/VCE-style study guide to analysing two numerical variables: describing scatterplots, interpreting Pearson's r and the coefficient…

    Difficulty
    Level 3 · Challenge
    Time
    25 min
  • Study Guide

    The Normal Distribution and z-scores

    An HSC/VCE-style study guide to the bell curve: calculating z-scores, comparing results from different tests, using the 68–95–99.7 rule,…

    Difficulty
    Level 3 · Challenge
    Time
    25 min
  • Worksheet

    Continuous Random Variables and Probability Density Functions

    A senior maths worksheet on continuous random variables: checking and completing probability density functions, finding probabilities by…

    Difficulty
    Level 3 · Challenge
    Time
    50 min
    Questions
    17 questions
    Answers
    Answers included

About this resource

Created by
Success Tutoring
Last reviewed
1 October 2026
How it was made
Written by our team

Free to print and share for personal, classroom and homeschool use. Please don't resell. Spotted an error? Let us know.