Question 230638
500 - 20% of 500 = 500 - .2*500 = 500 = 100 = 400


x% of anythikng is equal to x%/100% of that thing.


Example:

10% of x = .1 * x


20% of y = .2 * y


etc.


I would need a specific problem to go any further because I'm not sure what you are asking.