Figuring out Percent of Savings

Quick post on figuring percentages. I feel like an idiot, but I could not remember how to figure out what percentage of my total bill I saved on this last CVS trip. So, for those of us who are percentagally challenged (LOL) I give you this:


What percent of 20 is 30?
We have the original number (20) and the comparative number (30). The unknown in this problem is the rate. Since the statement is "(thirty) is (some percentage) of (twenty)", then the variable stands for the percentage, and the equation is:
30 = (x)(20)
30/20 = x = 1.5
Since x stands for a percentage, I need to remember to convert this decimal back into a percentage:
1.5 = 150%
Thirty is 150% of 20.

Or, to make it easier:

What percentage of 60.93 is 28.27? This would figure the percent of my total that i actually paid. To figure savings, subtract and then use the answer as your second number.

So, 28.27=60.93x
28.27/60.93=x
0.46=x
So my percent paid is 46%

My savings would be:
32.66=60.93x
32.66/60.93=x
0.54=x
My percent saved is 54%.

Ha. Now I remember doing this in school!