What do I need to know about modelling with progressions?
Many real-life situations can be modelled using progressions
If a quantity is changing repeatedly by having a fixed amount?added?to or?subtracted?from it then the use of?arithmetic progressions?is appropriate
If a quantity is changing repeatedly by a fixed?percentage,?or by being?multiplied?repeatedly by a fixed amount, then the use of?geometric progressions?is appropriate
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Exam Tip
Remember, an exam question won't always tell you to use progression methods, so you've got to be able to spot 'hidden' progression questions.
To help you do this, be suspicious of questions about savings accounts, salaries, sales commissions, profits and the like – these are often progression questions in disguise!