What expression can be used to find total discount of 30%

If you want to find a price of something after being discounted by 30%

Then

30/100 x The price of the item

Example; ):

Price of 20$ after being discounted by 30%

so,

30/100 x 20

= 6

We now know the total which is going to be discounted so

20-6 = 14$