Math CentralQuandaries & Queries


Question from Carlos:

If I calculate the percentage change between two fractions, say, 1/100 and 2/100, I get 100% change. Now, if I flip denominator and numerator, 100/1 and 100/2, and repeat the calculation, I get a 50% change. Why are the percentages different?

Thank you very much

Hi Carlos,

2/100 is twice 1/100 and thus when you invert them, 100/2 is half of 100/1. Said in terms of percentage, moving from 1/100 to 2/100 is a 100% increase and moving from 100/1 to 100/2 is a 50% decrease.


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