Grade five, CIE IGCSE Maths

Revision Notes

What is a reverse percentage?

A Reverse Percentage question is one where we are are given the value after a percentage increase or decrease and asked to find the value before the change.

How to do reverse percentage questions

You should do these in exactly the same way as Percentage Increase & Decrease questions!

Identify “before” & “after” quantities

  1. FIND percentage we want:
    • Increase – ADD percentage to 100
    • Decrease – SUBTRACT from 100
  2. Write down a STATEMENT connecting “before” and “after”:
    “after is a percentage of before”
  3. Write down the statement as an EQUATION using decimal equivalent
    remember “is” means “=”
  4. SUBSTITUTE and SOLVE

Example

Reverse Percentages Example, IGCSE & GCSE Maths revision notes

Question

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