How do you figure out the price of something if it says 20% off?

Is there a formula for figuring this out every time? If it says 20% off the list price (lets say $15) how do you figure out its real price? thanksHow do you figure out the price of something if it says 20% off?
You multiply $15 by .20(20%) and then subtract that number from 15.





So: y= x - (x*p)





Where y is the final price, x is the original price, and p is the percent you are taking off.How do you figure out the price of something if it says 20% off?
This is easiest for me:





10% of something is easy to find, you just move the decimal place over to the left. So say something is $15.00, then 10% is 1.50. If you want to figure out 20 or 30 or 40%, just multiple whatever you get from the 10% by 2, 3 or 4 respectively, and subtract that from the total.





$25.00 item is 20% off...20% of $25 is $5.00 (2.5 x 2), new price $20


$25.00 item is 30% off..30% of $25 is $7.50 (2.5 x 3), new price $17.50


$25.00 item is 40% off...40% of $25 is $10 (2.5 x 4), new price $15
20% off means 20/100ths off or 1/5 off.





For 20% or 1/5 off it's simple. 10% off is 1/10th - easy.


So, let's say $15 regular price.


10% is $1.50; 20% is twice that, or $3.00


$15 minus $3 is $12.





You can count in 10% levels for most discounts. For example - 40% off is 60% of the price - or half plus 10%.


So the item originally costs $43? 40% off?


Half $43 is $21.50; 10% is $4.30


So 60% of the price, or 40% off, is $21.50 + $4.30 or $25.80





Going backwards is a lot trickier. Easier with a calculator.


an item 15% off is actually 100-15=85% of original price.


Divide by 0.85 (or multiply by 100, then divide by 85) and you'll get the original price.


$15/0.85 = $17.65 original price before 15% discount.


hey, your cell phone works as a calculator too, doesn't it?
You're supposed to multiply the price by 20% and subtract the result from the original price.


I find it easier to move the decimal one place to the left and double that. Then subtract that from the price. Like if the thing cost $15. You move the decimal to the left and get $1.50. Double that to get $3 and subtract that from the price. $15 - $3 = $12.
if you know how to find 10% of something( if it was $15, 10% of that is $1.5) then you just double the number and you have 20%.
Take the sale price so let say $8 and divide it by the percentage of the price it actually is soo...





20% off $10 would be $8





$8 / 0.8 = $10