The flow rate of a coolant into a chemical reactor, RtR_tRt, is adjusted every minute such that the sequence of flow rates forms an arithmetic progression, where t t\,t is the time in minutes.
In the 4th minute, the flow rate is 40 L/min. The total volume of coolant delivered during the first 10 minutes is 325 L. Determine the initial flow rate, aaa, and the constant change in flow rate per minute, ddd.
A secondary auxiliary system has an initial flow rate of 6 L/min, which increases by 2 L/min each minute. The total volume delivered by this auxiliary system over n n\,n minutes is TnT_nTn. Find the value of n n\,n such that the total volume delivered by the primary system, SnS_nSn, is equal to TnT_nTn, where n>0n > 0n>0.
Practise Edexcel A Level Maths Sequences and Series with exam-style questions for A Level Maths. 156 questions 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, matched to the Edexcel A Level Maths (9MA0) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.
