Reverse percentage calculation?

Question

I know this is very basic question, but some how I want to understand this mathematics trick.
Let’s say I have $20,000 income this year which is increase of 25% from last year. When I multiply - 20,000 * .25, I get 5,000 but 15,000 (20,000 – 5,000) is not correct answer. Rather 16,000 is correct answer!

How do we calculate reverse percentage?

thanks for the responses. But I still didn't understand how did you arrive at 1.25 in the first place?

Answer 1

L = last year salary

T = this year salary

The 25% is of last year's salary

T = 1.25L {last years salary + 25%}

20000/1.25 = L

16000 = L

Answer 2

on your occasion x - 5d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e4% = 5d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e4 shows that the unique fee is larger than 5d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e4 yet this isn't 5d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e4% strengthen on 5d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e4 enable Unknown style be y So {(y - 5d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e4y)5d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e4} = 5d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e4 clean up for y {5d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e4y - 5d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e4y } = 5d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e4 5d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e4y = 5d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e4 So y = [5d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e4] y = 5d7ebdad819c5b227b0d222614c8e435d7ebdad819c5b227b0d222614c8e4294.11500000/80 5 So from the calculations we can see that 5d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e4% alleviation on 5d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e45d7ebdad819c5b227b0d222614c8e4 ends up in 5d7ebdad819c5b227b0d222614c8e435d7ebdad819c5b227b0d222614c8e4294.11500000/80 5

Answer 3

20,000 = (1.25 ) X so X = 20,000 / 1.25 = 16,000. 25% of 16,000 is 4000; 16,000 + 4,000 = 20,000.