Sequences and Series
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A trading company made a profit of £50 000 in 2006 (Year 1).

A model for future trading predicts that profits will increase year by year in a geometric sequence with common ratio rrr, r>1r > 1r>1.

The model therefore predicts that in 2007 (Year 2) a profit of £50 000 r r\,r will be made.

a.

Write down an expression for the predicted profit in Year nnn.

[1]
b.

The model predicts that in Year nnn, the profit made will exceed £200 000. Show that n>log⁡4log⁡r+1\displaystyle n > \frac{\log 4}{\log r} + 1n>logrlog4​+1.

[3]
c.

Using the model with r=1.09r = 1.09r=1.09, find the year in which the profit made will first exceed £200 000,

[2]
d.

find the total of the profits that will be made by the company over the 10 years from 2006 to 2015 inclusive, giving your answer to the nearest £10 000.

[3]

Sequences and Series Questions

Practise Edexcel A Level Old Maths Sequences and Series with exam-style questions for A Level Old Maths. 10 questions, matched to the Edexcel A Level Old Maths (9371) specification and written in Unit exams C1, C2, C3 and C4 plus two applied units (e.g. S1 and M1) 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.

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Sequences and Series Questions

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