In this question you must show detailed reasoning.
A manufacturing plant is implementing a 12-month program to reduce its industrial effluent. The effluent discharge is monitored at the start of each month.
The plant managers are evaluating two different reduction strategies.
Under strategy Plan A, the volume of effluent discharged will decrease by the same constant amount each month.
Calculate the effluent discharge in month 7 under Plan A. (3)
Under strategy Plan B, the volume of effluent discharged will decrease by a constant percentage each month.
Calculate the effluent discharge in month 7 under Plan B. Give your answer in m³ to one decimal place. (3)
The plant also generates a fixed volume of runoff, yyy m³, each month over the 12-month period. Given that:
(i) Find the maximum value of yyy, if strategy Plan A is used. (ii) Find the maximum value of yyy, if strategy Plan B is used. (5)
308 exam-style questions on OCR A Level Maths 1.4 Sequences and Series, covering 1.4.1 Binomial expansion for positive integer n, 1.4.2 Link to binomial probabilities, 1.4.3 Binomial expansion for rational n (A-level only), 1.4.4 Validity of the expansion (A-level only), 1.4.5 Sequences (A-level only), 1.4.6 Increasing, decreasing and periodic sequences (A-level only), 1.4.7 Sigma notation (A-level only), 1.4.8 Arithmetic sequences and series (A-level only), 1.4.9 Geometric sequences and series (A-level only), 1.4.10 Sum to infinity of a geometric series (A-level only), and 1.4.11 Modelling with sequences and series (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.