The probability that a specific variety of tomato seed fails to germinate is 0.06. A gardener plants several trays of these seeds.
Find the probability that
a tray containing 25 seeds has exactly 2 seeds that fail to germinate.
a larger batch of 100 seeds has more than 8 seeds that fail to germinate.
A commercial greenhouse plants a large shipment of 800 seeds.
Using a suitable approximation, find the probability that the greenhouse's shipment will contain less than 40 seeds that fail to germinate.
390 exam-style questions on OCR (MEI) A Level Maths 2.4 Probability Distributions, covering 2.4.1 Recognise binomial situations, 2.4.2 Probability of success p, 2.4.3 Calculate binomial probabilities, 2.4.4 Mean of the binomial distribution, 2.4.5 Expected frequencies for binomial, 2.4.6 Probability functions and discrete random variables, 2.4.7 Numerical probabilities for a simple distribution, 2.4.8 Normal distribution as a model (A-level only), 2.4.9 Shape of the Normal curve (A-level only), 2.4.10 Linear transformation and standardising (A-level only), 2.4.11 Symmetry and inflection of Normal curve (A-level only), 2.4.12 Calculate probabilities from a Normal distribution (A-level only), 2.4.13 Model with probability distributions, and 2.4 Probability Distributions. Each one has a worked solution and a mark scheme showing where the marks go.