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Problem #42 · September 7, 2026

Percentages

The price of the phone was increased by 25%25\%. By what percent must the new price be decreased so that the phone is at its original price again?
  1. A25%25\%
  2. B12,5%12{,}5\%
  3. C20%20\%
  4. D30%30\%
  5. E80%80\%

WORKED EXAMPLE

Solution

Let the original price be 100100 units; after the increase it becomes 125125. Now from 125125 one must subtract 2525 units: 25125=20%\frac{25}{125} = 20\%. The percent of decrease comes out smaller than the percent of increase, because it is taken relative to a larger number.
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