Quandaries and Queries


Name: Virginia
Who is asking: Other
Level of the question: Secondary

Question: How do you calculate a percentage back into a cost?

Example: $1,025.00 sale cost and I want to add 31 percent back into it for a list cost.

Thank you.



Hi Virginia,

If I understand correctly you have on sale for $1,025.00 and it says "marked down 31%". You want to know what it was selling for before it was marked down.

Think of what the store owner did in he the "marking down" process. She took the price, subtracted 31% of the price and got $1,025.00. To say it algebraically if $x was the price before it was marked down then

x minus 31% of x is 1,025.00

31% is 31 divided by 100, that is 0.31 so

x - 0.31 x = 1,025.00
(1 - 0.31) x = 1,025.00
0.69 x = 1,025.00
x = 1,025.00/0.69 = 1,485.50