Math and percentages

Question

Sorry but stuck on stupid on this one.

If I have a random number – let’s say 545 and I reduce it by 20%. It’s reduced by 109 making it 436.

But if I want to increase it back to 545 I have to add 25%

Edit: Ahhhh Thank you all for this! Makes perfect sense now!

In: Mathematics

Answer 1

I started with 545. I reduce it by 20% of 545 to 434.

To get back to the original number, I need to increase it again by 20% of 545. But clearly 20% of 545 is more than 20% of 436, so I need to add more than 20% (namely 25%) of 436.