The probability that a component is faulty is 0.04, independently of every other component. A batch consists of 25 components.
Find the probability that a batch contains exactly 2 faulty components.
Find the probability that a batch contains more than 2 faulty components.
Two batches are taken independently. Find the probability that exactly one of the two batches contains more than 2 faulty components.
390 exam-style questions on OCR A Level Maths 2.4 Statistical Distributions, covering 2.4.1 Discrete probability distributions, 2.4.2 Binomial distribution as a model, 2.4.3 Calculating binomial probabilities, 2.4.4 Mean and variance of the binomial (A-level only), 2.4.5 Normal distribution as a model (A-level only), 2.4.6 Probabilities using the normal distribution (A-level only), 2.4.7 Links to histograms, mean and standard deviation (A-level only), and 2.4.8 Selecting an appropriate distribution (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.