A chemical company produces two types of liquid fertilizer, 'GrowthPlus' and 'LeafBloom'. The volume, G G\,G ml, of 'GrowthPlus' used in a standard sprayer is modelled by G∼N(12.2,1.22)G \sim N(12.2, 1.2^2)G∼N(12.2,1.22). The volume, L L\,L ml, of 'LeafBloom' used in a standard sprayer is modelled by L∼N(5.8,0.52)L \sim N(5.8, 0.5^2)L∼N(5.8,0.52).
Two sprayers, one with each type of fertilizer, are selected independently at random. Find the probability that the volume of 'GrowthPlus' used is more than double the volume of 'LeafBloom' used.
'LeafBloom' is sold in 900 ml bottles. Assume that the volumes used by the 150 standard sprayers are independent. Find the probability that one bottle will be sufficient for 150 standard sprayers.
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.