Question

when a number is decreased by 20% of itself, the result is 128. what is the number?

Answer 1

The number was 160 because 5/4•128=160. 5/4 represents inverting 80% and multiplying it by the number to determine how the result became 128. For checking over all you have to do is do 4/5 or 80%•160 which shall give you 128.