How do you calculate an original price from a discounted price and a percentage rate?

For example: Say I know I get 30% off on a product and the discounted price is $20.65. Simply multiplying $20.65 by 30% (which equals $26.85) doesn't calculate the correct original price (which is $29.50), because it's a percentage of the discounted price, not the original price. So what's the formula for calculating this correctly to determine the original price?How do you calculate an original price from a discounted price and a percentage rate?
The current price is 70% of total, (100% - 30%). The way i've always done it is divide the current price by the current percentage, (20.65 / .70).How do you calculate an original price from a discounted price and a percentage rate?
SIMPLE, you know your total that is 29.50 that is = to 100%

so you have a discount of 30% but you want to now how much it is so;



29.50 =100%

x = 70%

29.50 ( 70 ) = 100 (x)

2065 /100 = x

x = 20.65