0
$\begingroup$

I'm trying to make a spreadsheet to split the house bills with my SO. I want to split the bills accordingly to our income so (the values are dummy) incomeA = 1000; incomeB = 600; percA = incomeA / (incomeA + incomeB); (0.625) percB = incomeB / (incomeA + incomeB); (0.375)

This is "our 50/50" and, in most of the bills is ok. If we have a bill of 40, I will play 25 (40 * 0.625) and she will pay 15 (40 * 0.375).

Now, let's say that we have a bill that I want to pay more than the "our 50/50" (75/25, for example) How can I translate our 50/50 ratio into that 75/25?

I don't really know how to put this in better words. Thanks in advance

$\endgroup$

closed as unclear what you're asking by GNUSupporter 8964民主女神 地下教會, Paul Frost, José Carlos Santos, Cesareo, user416281 Dec 2 '18 at 14:48

Please clarify your specific problem or add additional details to highlight exactly what you need. As it's currently written, it’s hard to tell exactly what you're asking. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

  • 1
    $\begingroup$ How about setting a multiplier to both 'incomeA' and 'incomeB'? The 50/50 you mention would set 'incomeA=1000*0.5=500' (the same for 'incomeB'). For the 75/25, 'incomeA=1000*0.75=750' (and similar for 'incomeB'). Good enough to get the percentages 'percA' and 'percB'. Now, I am not sure this is what you are asking. $\endgroup$ – DavidPM Nov 30 '18 at 16:56
  • $\begingroup$ @DavidPM yes! That works! Thanks! can you add that comment as an answer so I can accept it? $\endgroup$ – Bruno Camarneiro Nov 30 '18 at 17:17
1
$\begingroup$

For a simple solution, we set a multiplier (say $\lambda_1$) to incomeA and another one (say $\lambda_2$) to incomeB, in a way that $\lambda_1+\lambda_2=1$ (or $100$ if it results more intuitive).

In the case of the 75/25 ratio you mention in your example, we would set

$$\text{incomeA} = 1000*\lambda_1=1000*0.75$$ $$\text{incomeB} = 600*\lambda_2=600*0.25$$

We would do the same for the 50/50 example, with $\lambda_1=\lambda_2=0.5$.

The true amounts of incomeA and incomeB do not really matter since we are mostly interested in getting the percentages percA and percB.

$\endgroup$

Not the answer you're looking for? Browse other questions tagged or ask your own question.