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Old March 29, 2012, 12:39 AM
Dien Rice Dien Rice is offline
Onwards and upwards!
 
Join Date: Aug 2006
Posts: 2,526
Default Re: Was anybody here awake in 8th grade math?

Quote:
Originally Posted by Bozo View Post
This is driving me nuts. I have figured it out before and then forgot how.

Some amount, less 30% of that amount = $8

What is the amount, and how in the heck can I figure it for myself.

If I get an answer, I'm carving it on the back of my hand this time.
Hi Boz,

No need to mutilate your hand!

30% is just 30/100, which is 0.3 .

So you can set it up as an algebra equation...

Let's call "some amount" as "x".

So, "some amount, less 30% of that amount = $8" becomes

x - 0.3 x = 8

Rearranging it becomes

x (1 - 0.3) = 8 ... but since (1 - 0.3) = 0.7, we can write

0.7 x = 8 ... now dividing each side by 0.7 gives us

x = 8 / 0.7 ... or

x = 11.43 (rounding it off).

If you plug 11.43 in the original equation, you see it works out!

Best wishes,

Dien
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