# Business MathNeed help adding a percentage cost to a selling price!

#### mrmikepan

##### New member
Sorry if this question sounds stupid...

I know there's something obvious that I'm missing (maybe not) but its taking me forever to figure out on my own.

What were trying to do is cover all costs associated for the sale within the selling price.

We have-
• Flat Fees: $4.70 • Shipping:$5.20
• Material costs: $100 • And we want to include a 35% Profit of Material Costs ($35) within the selling price.
• And last but not least, the part I can't figure out is how to add a 11.9% fee to the selling price (applied after the sale of everything combined).

I need to have it be exact! So if the fees were deducted I would be left with 135 dollars. ($100 + the 35% profit) If I add 11.9 percent of the selling cost, the 11.9 percent value will have changed because I'm adding the dollar amount to the total...right? So how can I account for it? By raising the 35 percent profits to something more? I just need to be sent in the right direction so that I could do this alone next time. Not necessarily looking for the answer, I'm looking for the procedure/the way to go about this type of calculation which I'm sure happens all the time in business. Thanks for all your help! Last edited: #### tkhunny ##### Well-known member MHB Math Helper Re: Need up adding a percentage cost to a selling price! Just a little algebra. •Flat Fees:$4.70
•Shipping: $5.20 •Material costs:$100
•And we want to include a 35% Profit of Material Costs ($35) within the selling price. •And last but not least, the part I can't figure out is how to add a 11.9% fee (applied after the sale) of everything combined to the selling cost. (Selling Cost) = 4.70 + 5.20 + 100.00*1.35 + 0.119*(Selling Cost) Some algebra (Selling Cost) - 0.119*(Selling Cost) = 4.70 + 5.20 + 100.00*1.35 More algebra (Selling Cost)(1 - 0.119) = 4.70 + 5.20 + 100.00*1.35 Still More (Selling Cost) = (4.70 + 5.20 + 100.00*1.35)/(1 - 0.119) Now for arithmetic (Selling Cost) = (9.90 + 135.00)/(0.881) = 144.90/0.881 = 164.48 Check it out! 164.48*0.119 = 19.57 164.48 - 19.57 = 144.91 and this is not quite 144.90 only because of rounding. #### mrmikepan ##### New member Re: Need up adding a percentage cost to a selling price! Just a little algebra. •Flat Fees:$4.70
•Shipping: $5.20 •Material costs:$100
•And we want to include a 35% Profit of Material Costs ($35) within the selling price. •And last but not least, the part I can't figure out is how to add a 11.9% fee (applied after the sale) of everything combined to the selling cost. (Selling Cost) = 4.70 + 5.20 + 100.00*1.35 + 0.119*(Selling Cost) Some algebra (Selling Cost) - 0.119*(Selling Cost) = 4.70 + 5.20 + 100.00*1.35 More algebra (Selling Cost)(1 - 0.119) = 4.70 + 5.20 + 100.00*1.35 Still More (Selling Cost) = (4.70 + 5.20 + 100.00*1.35)/(1 - 0.119) Now for arithmetic (Selling Cost) = (9.90 + 135.00)/(0.881) = 144.90/0.881 = 164.48 Check it out! 164.48*0.119 = 19.57 164.48 - 19.57 = 144.91 and this is not quite 144.90 only because of rounding. OMG TY! I don't know why this was taking me so long, for some reason when I was trying to do it in my head trying to setup the calculation I needed in excel. I felt like I was going in circles. Its nice to get things explained clearly, ty! #### mrmikepan ##### New member Re: Need up adding a percentage cost to a selling price! Just a little algebra. •Flat Fees:$4.70
•Shipping: $5.20 •Material costs:$100
•And we want to include a 35% Profit of Material Costs (\$35) within the selling price.
•And last but not least, the part I can't figure out is how to add a 11.9% fee (applied after the sale) of everything combined to the selling cost.

(Selling Cost) = 4.70 + 5.20 + 100.00*1.35 + 0.119*(Selling Cost)

Some algebra

(Selling Cost) - 0.119*(Selling Cost) = 4.70 + 5.20 + 100.00*1.35

More algebra

(Selling Cost)(1 - 0.119) = 4.70 + 5.20 + 100.00*1.35

Still More

(Selling Cost) = (4.70 + 5.20 + 100.00*1.35)/(1 - 0.119)

Now for arithmetic

(Selling Cost) = (9.90 + 135.00)/(0.881) = 144.90/0.881 = 164.48

Check it out!

164.48*0.119 = 19.57
164.48 - 19.57 = 144.91 and this is not quite 144.90 only because of rounding.
One little thing I wanted to ask:
The formula is -

......... x = 4.70 + 5.20 + 100*1.35 + 0.119x right?
-0.119x .......................... - 0.119x

0.881x = 4.70 + 5.20 + 100*1.35
0.881 ................. 0.881

x = (4.70 + 5.20 + (100*1.35))/0.881
x = (9.90 + 135)/0.881
x = 144.90/0.881
x = 164.47 (164.47*0.119) = 19.57

164.47 - 4.70 = 159.77
159.77 - 5.29 = 154.57
154.57 - 19.57 = 135!!

Yay! I guess I answered my own question