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.
67 exam-style questions on OCR A Level Maths 2.4.4 Mean and variance of the binomial (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.