# HP Forums

Full Version: Help needed
You're currently viewing a stripped down version of our content. View the full version with proper formatting.
Hi all. Im new here. My 48g sadly passed away after many years of great service - so i purchased a HP Prime. To my own supprise I realised the Prime does not have the Eq Lib.
But my biggest need is an app to calculate "selling price" "margin" or "cost price" with any two of the variables availible! Untill i have learnt the programming is there someone that could help with the source code? Regards
(01-03-2014 01:12 PM)Luano Wrote: [ -> ]But my biggest need is an app to calculate "selling price" "margin" or "cost price" with any two of the variables available! Until i have learnt the programming is there someone that could help with the source code? Regards

The easiest way to do this is to use the Solve App. Enter the formula C=S*(100-M)/100 in the symbolic view and then press the Num key to enter the numeric view, where you can enter the known values and press Solve to find the unknown value.
Hi Micheal,
Thanks for your help! I think the formula should be s=c*(100+m)/100
My progress through the manual is at a steady pace.
Regards
(01-03-2014 04:14 PM)Luano Wrote: [ -> ]I think the formula should be s=c*(100+m)/100

I don't know about the formula, but I would suggest you use capital letters. Otherwise, you will need to create user variables before you can enter them in the Solve App.
Thanks again,
I do cash register systems including stock control for a living. The correct formula linking selling price, margin and cost price (disregarding such trivialities as VAT or other taxes) is:
S = C * 100 / (100 - M)

The important distinction is between margin and mark-up. Margin is profit as a fraction of the selling price, mark-up is profit as a fraction of the cost price. Most stock control systems are designed to work on margins but some of them (not ours) implement mark-up in error since that is simpler to handle.

The times I've had to explain this distinction to our customers! The formula bears some resemblance to the formulas of relativity, so you can't get a margin of 100% (since that would make the selling price infinite) unless you start with a supplier's freebie (C = 0) in which case the entire selling price is profit irrespective of what you charge for it - analogous to a massless particle (e.g. a photon) always travelling at the speed of light irrespective of its energy.
(01-04-2014 10:45 AM)Curlytop Wrote: [ -> ]The formula bears some resemblance to the formulas of relativity, so you can't get a margin of 100% (since that would make the selling price infinite) unless you start with a supplier's freebie (C = 0) in which case the entire selling price is profit irrespective of what you charge for it - analogous to a massless particle (e.g. a photon) always travelling at the speed of light irrespective of its energy.
1+ for this nice analogy!
Reference URL's
• HP Forums: https://www.hpmuseum.org/forum/index.php
• :