This study notes covers Worked Example 4: Reverse Percentage within Percentages for GCSE Mathematics. Revise Percentages in Number for GCSE Mathematics with 14 exam-style questions and 22 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 11 of 16 in this topic. Use this study notes to connect the idea to the wider topic before moving on to questions and flashcards.
Worked Example 4: Reverse Percentage
After a 20% discount, a jacket costs £64. What was the original price?
Solution
After 20% off, price is 80% of original
80% of original = £64
1% of original = 64 ÷ 80 = 0.8
100% of original = 0.8 × 100 = £80
Check: £80 × 0.8 = £64 ✓
Practice questions for Percentages
Which calculation correctly finds 35% of £240 using the decimal method?
Which formula correctly expresses one quantity as a percentage of another?