An item went up 20%, then down 20% — how did the price change?
Problem
The price of an item first rose by 20%, and then the new price fell by 20%. By what percentage does the final price differ from the original one?
Answer
The final price is 4% below the original one
Step-by-step solution
Step 1. Denote the initial price
Let the initial price be 100 (a convenient number — percentages are easier to compute). Everything else is expressed in terms of it.
Step 2. An increase of 20%
After the rise of 20% the price became .
2 more steps — unlocked after you sign in:
- Step 3. A decrease of 20%
- Step 4. Compare with the start
Free · takes a minute
Common mistakes
- ✗
Assuming that +20% and −20% cancel each other out and the price does not change — that is wrong.
- ✗
Taking the second percentage from the initial price instead of from the new one.