Maths !!!HELP!!!

[unicyclenz]

Hey all

I’m stuck on a bit of reverse percentage maths

At my work we sell items with a 20% + GST commission and a $5 Fee

The problem i have is as follows.

A vendor who owns something we are selling wants to get $1000 dollars for there item. I need to work out what price we would need to sell items

Heres what i’ve got so far but could be wrong

Commision (X)=a*.20
GST(Y)= X*0.125

Where a = price we are offered

A - (X+Y) - 5 = B

where b is what the vendor gets

A-((A*.20)+((A*.20)*0.125))-5=B

The above equation is for working out what the vendor gets starting with what we are offered

I need the equation to be =A instead of =B

I cant get it to work,

I hope this makes sense to someone:D

Cheers

Dan

[Daytripper63]

1000.00 divide by.80 = 1250.00 divide this number by .875 = 1428.57 plus the 5.00 fee = 1433.57
edit: Divide by will give you true margin Never multiply to calculate a sell price

[unicyclenz]

Thanks for your reply

Im still confused though

for example

if i sell something for $120
the commision is $24 with a futher $3 gst on that commision (the gst is only on the commision)
Add onto that a $5 fee and they get back $88

Doing it backwards using the dividing method i get

88/.80=110 110/.875=125.7 125.7+5=130.7

which is more than i started with

Am i adding wrong?, man i should have listened more in maths

Cheers

Dan

[phlegm]

You need to carefully define what each value is so that you can correctly apply math.

Try something like this:

g = gross (what you sell it for)

p = profit (how much you give to the vendor) = $1000 in your example

f = fee = $5

c = commission = 0.20 * g

t = tax = 0.125 * c = 0.125 * 0.20 * g

Then,

g = p + f + c + t = 1000 + 5 + (0.20 * g) + (0.125 * 0.20 * g)
= 1005 + (0.225 * g)

So, g = 1296.78

You owe me a KH-Schlumpf geared hub.

[Daytripper63]

@unicyclenz

Thanks for your reply

Im still confused though

for example

if i sell something for $120
the commision is $24 with a futher $3 gst on that commision (the gst is only on the commision)
Add onto that a $5 fee and they get back $88

Doing it backwards using the dividing method i get

88/.80=110 110/.875=125.7 125.7+5=130.7

which is more than i started with

Am i adding wrong?, man i should have listened more in maths

Cheers

Dan

Why are you starting with 88.00 that number is not a product of a calculation 96.00 is the result of 120.00 less the 20% commision which is figured by 120.00 X .80 = 96.00 and from this number you deducted your GST and 5.00 fee to end up at your 88.00 so to do the math in reverse you need to start with 88.00 plus back in your 5.00 fee and your 3.00 GST which gives you your 96.00 and now your ready to Divide by .80 which brings you back to 120.00

To figure price mark-up you will DIVIDE by, and to figure out Discount you will multiply by the sell price. ( The easiest way to remember this is to think of it backwards:When it comes to your calculations, DIVIDING a number will actually do MARK-UP and MULTIPLYING a number will actually figure the DISCOUNT )

Example,
sell something for $120.00 and you get a 20% commission, to correctly figure your comm. you would take the sell price of 120.00 X .80 = 96.00
You will always start with 100% so 20% in either direction will be .80 and 30% would be .70 and so on,for calculating purposes.

[unicyclenz]

[QUOTE=Daytripper63]
Why are you starting with 88.00 that number is not a product of a calculation 96.00 is the result of 120.00 less the 20% commision which is figured by 120.00 X .80 = 96.00 and from this number you deducted your GST and 5.00 fee to end up at your 88.00 so to do the math in reverse you need to start with 88.00 plus back in your 5.00 fee and your 3.00 GST which gives you your 96.00 and now your ready to Divide by .80 which brings you back to 120.00/QUOTE]

I start with 88 as this is what the vendor said they require. For instance the vendor says that they have to get a check for 88 dollars, now we need to figure out what should be the minimum we sell for to make sure she gets $88.

So i need to know what is the number that when commision,gst and charges are taken off will result in a value of 88

I thought it would be simple but every time i try it i cant get the wrong answer.

another example. if the vendor must get a check for at least $1400 what is the minimum we can sell the item for if we charge a 20% commission + gst on that commission

Sorry if i’m confusing people, i’m rather tired at the moment.

Thanks for all the replys

Dan

[saskatchewanian]

this should work

I made up an excel sheet for you but I cant seem to make it an attachment

basically to get the amount needed to satisfy a vendor is Total = (vendor price + $5)/0.775

I will run through the calculations quick for you

Total = T
Commision = C
GST = t
Vendor = V

T=V+C+t+5

C=0.2T

t=0.125C
t=0.125(0.2T)
t=0.025T

V=T-C-t-5
V=T-0.2T-0.025T-5
V=0.775T-5
0.775T-5=V <—I am just switching the sides
0.775T=V+5
T=(V+5)/.775

use T=(V+5)/.775 if you want to find out the minimum you can sell the item for and V=0.775T-5 if you want to see how much money goes to the vendor.

[Daytripper63]

[quote=“unicyclenz”]

@Daytripper63

Why are you starting with 88.00 that number is not a product of a calculation 96.00 is the result of 120.00 less the 20% commision which is figured by 120.00 X .80 = 96.00 and from this number you deducted your GST and 5.00 fee to end up at your 88.00 so to do the math in reverse you need to start with 88.00 plus back in your 5.00 fee and your 3.00 GST which gives you your 96.00 and now your ready to Divide by .80 which brings you back to 120.00/QUOTE]

I start with 88 as this is what the vendor said they require. For instance the vendor says that they have to get a check for 88 dollars, now we need to figure out what should be the minimum we sell for to make sure she gets $88.

So i need to know what is the number that when commision,gst and charges are taken off will result in a value of 88

I thought it would be simple but every time i try it i cant get the wrong answer.

another example. if the vendor must get a check for at least $1400 what is the minimum we can sell the item for if we charge a 20% commission + gst on that commission

Sorry if i’m confusing people, i’m rather tired at the moment.

Thanks for all the replys

Dan

88.00 /.80 = 110.00 and by my figures with the info you supplied GST should be 8.3% which equals .917 ( remember always start with 100 and subtrat the percent you want in order to get your number )
110.00 - 88.00 =22.00
22.00 X .917 = 20.17
22.00 - 20.17= 1.83 which is your GST
plus 5.00 fee
So 22.00 + 1.83GST + 5.00 = 28.83 + 88.00 = 116.83

[Naomi]

@unicyclenz

At my work we sell items with a 20% + GST commission and a $5 Fee

A-((A*.20)+((A*.20)*0.125))-5=B
I need the equation to be =A instead of =B

Dan

I don’t know what GST is or how it is applied, but converstion of the equation you have given to be of the form A=, rather than B= is simplicity.

In very easy steps, for you say you are having some difficulty in understanding what others have said.

A-((A*.20)+((A*.20)*0.125))-5=B

A- (A0.20 +A0.20*0.125) = B+5

A- A(0.20 +0.200.125)=B+5
A-A (0.20+0.025) =B+5
A-A0.225 =B+5
A(1-0.225) =B+5
A* 0.775=B+5
A=(B+5)/0.775

Which gives the answer that Phlegm has already quoted 1296.78

[ivan]

I honestly have less difficulty understanding differential calculus than getting my head around all these ts, As, GSTs and all that.

Maybe it’s just the presentation. Or maybe it’s just too boring.

Or maybe both.

[unicyclenz]

Cheers everyone

A=(B+5)/0.775

I knew it had to be simple but couldn’t figure it out

Thanks

Dan:D

[ducestecum]

math help

this may help. Think of your anticipated selling price in terms of a percentage.
which would be 100%. Your vendor cost is less than 100%.

$1000.00 times 20%=$1200.00(1000.00x1.20) then multiply by your GST(1.XX) then add your 5.00. Now you have your estimated selling cost. don’t divide, multiply by 1.XX( your markup percentage).