Quandaries and Queries
  

 

I am not a student but somebody who should know the answer but have forgotten in the course of time.
 
Can you please help.
 
the sum of eg $130 includes the markup of 30%.
 
However I need to calculate the percentage to apply to the $130 to assess the cost ie $100.
 
Sound simple but I have tried every which way.
 
I am grateful
 
Norman
 
 

 

Hi Norman,

In your example you know that $130 is composed of a cost of $100 and a markup of 30%. that is

$100 plus 30% of $100 is $130 or
$100 + 0.30 $100 = $130 or, one more time
$100 1.30 = $130

Now if you are told that the ticket price of an item is $128.80 and this includes a 12% markup the calculation analogous to the above would be

(unknown cost) 1.12 = $128.80

and hence

unknown cost = $128.80/1.12 = $115

Now you can check that this is correct

$115 plus 12% of $115 = $115 + $13.80 = $128.80

Penny

 
 

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