X+15% = 20 000 I am so disappointed with myself (computing w/ VAT)

[macedo7]

Hi everyone,

I am so disappointed with myself as I used to be really good at math. Its been a long time but I cannot believe why I can figure this out.

I have a total of 20 000 which I made a deal with a client I would charge which includes my countries VAT of 15%. I am trying to work out what the value must be before VAT to put it on my invoice.

In my mind the logical formula would be:

X+15%=20 000

What is wrong here? Am I working with the rules of algebra incorrectly when dealing with percentages? I converted the 15% to decimal to make it 0.15.

Please help.

 

[Deleted member 4993]

Hi everyone,

I am so disappointed with myself as I used to be really good at math. Its been a long time but I cannot believe why I can figure this out.

I have a total of 20 000 which I made a deal with a client I would charge which includes my countries VAT of 15%. I am trying to work out what the value must be before VAT to put it on my invoice.

In my mind the logical formula would be:

X+15%=20 000

What is wrong here? Am I working with the rules of algebra incorrectly when dealing with percentages? I converted the 15% to decimal to make it 0.15.

Please help.

step 1 - Define your variables (unknowns) explicitly

For this problem :

X = Value of the object prior to applying VAT (I am assuming that was what you wanted)

step 2 - Apply given conditions and create equations:

Amount VAT imposed = 0.15 * X

Total price = VAT + Value prior to VAT

20000 = 0.15 * X + X

20000 = X * (1 + 0.15) ...... continue.....

 

[HallsofIvy]

You should realize that "X+ 15%" just does not make sense! You always have to talk about "percent" of something. You can't just write "+ 15%". 15% of what? Here the value added tax is 15% of the price of the item: 15% of X. So you should have "X+ 15% of X" or X+ 0.15X= 1.15X.