If A's Salary Is 25% Higher Than B's Salary, How Much Per Cent Is B's Salary Lower Than A's?

20.

If B=100 then A=125.  Thus, B is 25 less than A.  Since A = 125, you take 25/125 to get you answer: .2 or 20%

Don't know why I'm answering this but you basically answered the question by saying 25%.
What I think you meant was if A salary = 100% than B salary = 100-25=75%.
SO find the answer by dividing salary B 75 by Salary A 100 and then x by 100. :D

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