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
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
and hence
Now you can check that this is correct
Penny 

