# How to achieve a desired result by reducing numerator and denominator simultaneously

• Sep 18th 2009, 12:42 PM
cz22
How to achieve a desired result by reducing numerator and denominator simultaneously
Hi, hopefully someone can help, am not all that mathematically minded!!

If I have the following
Numerator 300
Denominator 250

Divide them I get
1.2

I need to attain a result of 1.25. How can I calculate the minimum amount to subtract off both to attain this result. If I take 1 off the numerator I must take 1 off the denominator, if 2 off the numerator then 2 off the denominator and so on.

Any help greatly appreciated, are there excel functions to these effect? add ins?
• Sep 18th 2009, 12:55 PM
e^(i*pi)
Quote:

Originally Posted by cz22
Hi, hopefully someone can help, am not all that mathematically minded!!

If I have the following
Numerator 300
Denominator 250

Divide them I get
1.2

I need to attain a result of 1.25. How can I calculate the minimum amount to subtract off both to attain this result. If I take 1 off the numerator I must take 1 off the denominator, if 2 off the numerator then 2 off the denominator and so on.

Any help greatly appreciated, are there excel functions to these effect? add ins?

There is a probable chance that I've misread this question >.<

$\frac{300-x}{250-x} = \frac{5}{4}$

Solve for x

Spoiler:
$4(300-x) = 5(250-x)$

$1200 - 4x = 1250 - 5x$

$x = 50$
• Sep 18th 2009, 01:10 PM
cz22
You'll have to spell it out to me... apologies it's been too long since I last sat in a maths class!
• Sep 18th 2009, 01:13 PM
e^(i*pi)
Quote:

Originally Posted by cz22
You'll have to spell it out to me... apologies it's been too long since I last sat in a maths class!

Did you check the spoiler?

$1.25 = \frac{5}{4}$. I used fractions for the fun of it.

You say you have to subtract the same amount from both the top and the bottom until the quotient equals the value above.

To determine this number we give it a letter to make it easier to find. In this case it's x. x is defined as the value that will make the above part correct. As it has to be the same both values must be x so we have an equation in x and only x.

Therefore we can solve like any fraction to find x
• Sep 18th 2009, 02:16 PM
cz22
Many thanks, never used the site before, didn't notice the spoiler.