Need Help figuring out the 3rd Number

[kls0654]

I have only 2 numbers

1. 15%
2. 161.80

I have to get after the deal is done $161.80 and the the other guy have to get 15% of the deal.

So the total deal will be $190.35 - (161.8 is a 15% decrease of 190.35.)

How can I get to this number ($190.35) in Excel or in a Calculator , when I have only the 2 other numbers (1. 15% 2. 161.80)

Thanks in Advance

 

[Deleted member 4993]

I have only 2 numbers

1. 15%
2. 161.80

I have to get after the deal is done $161.80 and the the other guy have to get 15% of the deal.

So the total deal will be $190.35 - (161.8 is a 15% decrease of 190.35.)

How can I get to this number ($190.35) in Excel or in a Calculator , when I have only the 2 other numbers (1. 15% 2. 161.80)

Thanks in Advance

Please show us what you have tried and exactly where you are stuck.

Please follow the rules of posting in this forum, as enunciated at:

https://www.freemathhelp.com/forum/threads/read-before-posting.109846/#post-486520

Please share your work/thoughts about this assignment.

 

[JeffM]

[MATH]x = \text { what you get}\\ y = \text {percentage Joe gets in DECIMAL form}\\ p =\text {price}\\ p - py = x \implies p(1 - y) = x \implies p = \dfrac{x}{1 - y}.[/MATH]Let's try it with your specific example.

[MATH]x = 161.80, \ y = 15 \% \implies \\ p = \dfrac{161.80}{1 - 0.15} = \dfrac{161.80}{0.85} \approx 190.35 [/MATH]CHECK

[MATH]190.35 * 0.15 = 28.5525\\ 190.35 - 28.5525 = 161.7975 \approx 161.80. \ \checkmark[/MATH]P.S. This is NOT advanced math; rather it is elementary algebra.

 

[Dr.Peterson]

I have only 2 numbers

1. 15%
2. 161.80

I have to get after the deal is done $161.80 and the the other guy have to get 15% of the deal.

So the total deal will be $190.35 - (161.8 is a 15% decrease of 190.35.)

How can I get to this number ($190.35) in Excel or in a Calculator , when I have only the 2 other numbers (1. 15% 2. 161.80)

Thanks in Advance

Here's how to think of it without algebra:

Your 161.80 is what you get when you subtract 15% of an unknown amount (the 190.35). When you subtract 15% of something from 100% of it, what remains is 85% of it. So 161.80 is 85% of the unknown -- that is, 0.85 times the unknown.

To undo that multiplication, you divide: 161.80 divided by 0.85 = 190.35294..., which rounds to 190.35. That's the answer.

So in general, to find the whole amount, when you know the result of decreasing it by some percentage, just subtract the percentage from 100%, and divide by that. That's what JeffM's formula tells you.