# Calculate x % of y easily with this trick

March 08, 2019

Say your friend comes up to you with this question “What is 63% of 25?”. If you do not have a pen and a paper handy then solving this question will not be straightforward. One approach, that most people take, is to find a small percent of the number, say x% of 25 such that x can take you easily to 63. So here you may find 3% of 25 and then multiply it by 21 to get you to 63, which again is a pain.

So there must a simpler way to do this; and there is

What if I say,

The statement seems untrue at first but in fact it is very true. The proof is really very simple and requires a basic math to understand its elegance

One interpretation of above euality is that you can trade numbers as per your convenience and you can use the one that is simpler to fraction w.r.t 100 you can use it as y, making your life easy again.

Coming back to the question, since we have established

and hence finding the answer is as easy as

Hope you find this property pretty handy Cheers