Math Help - % Decrease in price

1. % Decrease in price

If a compact disc that usually sells for $12.95 is on sale for$9.95, then what is the percent decreast in price, rounded to the nearest whole number?

I was not sure of the formula...but I did come out using my common sense after my equation to an answer of 23%. I did the following

% decrease = (decrease amount / original amout ) * 100%
% decrease = (9.95 / 12.95) * 100%
% decrease = .77 or 77%

then

I just used common sense to know it must be 23%...but what equation could I use?

2. Originally Posted by thecapaccino
If a compact disc that usually sells for $12.95 is on sale for$9.95, then what is the percent decreast in price, rounded to the nearest whole number?

I was not sure of the formula...but I did come out using my common sense after my equation to an answer of 23%. I did the following

% decrease = (decrease amount / original amout ) * 100%
% decrease = (9.95 / 12.95) * 100%
% decrease = .77 or 77%

then

I just used common sense to know it must be 23%...but what equation could I use?
yes, it should be 23%

there are many approaches to a problem like this. but if you want a straightforward formula, here it is:

this will work for increases or decreases

%change = (change in amount / original amount)*100%