eli5 The percentage rule

Question

Can someone explain how/why X% of Y is equal to Y% of X? I know it’s true but I can’t figure out why. Thanks!

In: 10

Answer 1

A “per cent” is just “divided by 100”.

50 percent is 50 / 100.

50 percent of a price is fifty one-hundredths of the original cost.

It’s just a fraction.

so X% of something is just (X / 100) times by Y.

Which is mathematically the same as (Y / 100) times by X.

x*y/100 is the same as y*x/100.

Answer 2

A “per cent” is just “divided by 100”.

50 percent is 50 / 100.

50 percent of a price is fifty one-hundredths of the original cost.

It’s just a fraction.

so X% of something is just (X / 100) times by Y.

Which is mathematically the same as (Y / 100) times by X.

x*y/100 is the same as y*x/100.