Formula working backwards from finished price
 

I am stuggling with the following formula. If I have a unit that is worth
$100 in Col A and I have another column representing a 10% on the $100 and
then Col. C representing a 17.5% charge on the $100 and Col D representing
A+B+C this is equal to $127.50. But I want to go from Col D $127.50 to
establish what Col C is at 17.5% and Col B is at 10% and therefore Col A is
eqal $100.

What formulas do I need to enter into Cols C,B,A . I hope this clear as I
have been going crazy trying to get this.

Thanks In ananticipation
Eqa

Formula working backwards from finished price
 

"Eqa" wrote...
I am stuggling with the following formula. If I have a unit that is worth
$100 in Col A and I have another column representing a 10% on the $100 and
then Col. C representing a 17.5% charge on the $100 and Col D representing
A+B+C this is equal to $127.50. But I want to go from Col D $127.50 to
establish what Col C is at 17.5% and Col B is at 10% and therefore Col A is
eqal $100.
....

Algebra helps. a = 100, b = a * 0.10 = 10, c = a * 0.175 = 17.50, d = a + b
+ c = a * (1 + 0.10 + 0.175) = a * 1.275 = 127.50.

Given d = 127.50,

a = d / 1.275 = 100, - A1: =D1/1.275

b = a * 0.10 = d * 0.10 / 1.275 = 10 - B1: =D1*0.1/1.275 or =A1*0.10

c = a * 0.175 = d * 0.175 / 1.275 = 17.50 - C1: =D1*0.175/1.275 or
=A1*0.175

Formula working backwards from finished price
 

Thanks Harlan I was going around and around. That is great!!!

"Harlan Grove" wrote:

"Eqa" wrote...
I am stuggling with the following formula. If I have a unit that is worth
$100 in Col A and I have another column representing a 10% on the $100 and
then Col. C representing a 17.5% charge on the $100 and Col D representing
A+B+C this is equal to $127.50. But I want to go from Col D $127.50 to
establish what Col C is at 17.5% and Col B is at 10% and therefore Col A is
eqal $100.
....

Algebra helps. a = 100, b = a * 0.10 = 10, c = a * 0.175 = 17.50, d = a + b
+ c = a * (1 + 0.10 + 0.175) = a * 1.275 = 127.50.

Given d = 127.50,

a = d / 1.275 = 100, - A1: =D1/1.275

b = a * 0.10 = d * 0.10 / 1.275 = 10 - B1: =D1*0.1/1.275 or =A1*0.10

c = a * 0.175 = d * 0.175 / 1.275 = 17.50 - C1: =D1*0.175/1.275 or
=A1*0.175