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)
178 exam-style questions on Edexcel A Level Maths Sequences and Series, covering 3.1 Arithmetic Sequences, 3.2 Arithmetic Series, 3.3 Geometric Sequences, 3.4 Geometric Series, 3.5 Sum to Infinity, 3.6 Sigma Notation, 3.7 Recurrence Relations, and 3.8 Modelling with Series. Each one has a worked solution and a mark scheme showing where the marks go.