What's that formula again?

I never could remember how to figure percents this way

[MatthewHSE]

Say I need to know what number 100 is 20% more than, like so:

x + 20% = 100

What's the formula to work that out? This is the one part of percentages I never could get right, even five minutes after I had learned it yet again....

The first person to answer this one clearly and concisely shall have the honor of being permanently Scrapbooked [addons.mozilla.org] ;)

[edited by: MatthewHSE at 1:05 am (utc) on May 23, 2008]

[briggidere]

(x / 120) * 100 = y

100/120= 0.8333

0.8333 * 100 = 83.333 (answer)

Test - (83.333 / 100) * 120 = 100

[wyweb]

I can never remember that either.

[ringsoft]

I've made a note of that so I don't need to remember it.

But I can't remember where I put the note...

[jecasc]

Say I need to know what number 100 is 20% more than, like so:

x + 20% = 100

100-20% = x

That was easy...

[blend27]

It is not important to know everything, but it is important to know where to look for the answer, as well as how to find the answer. Once one figures out the routine it is fairly easy to apply that formula to pretty much every situation one is faced with... Thus pointers in(to) memory are faster than inline evaluation.

[MatthewHSE]

100-20% = x

That was easy...

I may not have known the right answer, but I knew that was wrong! ;) 20% of 80 is 16, meaning 96, not 100, is 20% more than 80. See briggidere's test case...

[webfoo]

I don't know... you're MATHew, you should be able to figure this out.

[topr8]

to see what 100 is 20% more than

100 / 1.20 ( of course this is the same as 100/1.2 but i use 1.20 to be clear.