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.
Write down an expression for the predicted profit in Year nnn.
The model predicts that in Year nnn, the profit made will exceed £200 000. Show that n>log4logr+1\displaystyle n > \frac{\log 4}{\log r} + 1n>logrlog4+1.
Using the model with r=1.09r = 1.09r=1.09, find the year in which the profit made will first exceed £200 000,
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.
9 exam-style questions on Edexcel A Level Old Maths Sequences and Series. Each one has a worked solution and a mark scheme showing where the marks go.