How to calculate percentage taken off of an item?

please give brief understandable answers!How to calculate percentage taken off of an item?
Take the percent as a decimal (move the decimal place 2 places to the left so 15% is 0.15), subtract that from 1 (100%), and then multiply it by the price of the item. For example, if a shirt you want is $49.99 ($50) and it's 15% off then you'd multiply 50 by .85 and get that it's about $42.50, obviously before tax is applied.
Suppose you are having x quantity of any thing.You want to take 10% of it then do it like this





10% of x will be x*(10/100)





Y% of x will be x*(Y/100)



50% of x will be x*(50/100)How to calculate percentage taken off of an item?
Just take the amount taken off, divide that by the original amount and then multiply by 100. Then you will have your answer there.
If say $45.00 with 20% discount you multiplied 45*.2=$9.00 discount.

But if say $45.00-$9.00 what percent it is the discount then 9/45=0.2 or 20%.How to calculate percentage taken off of an item?
Suppose a widget usually costs $100.

sale price + discount = $100



You buy it on sale for $75.

The sale price is 75% of the regular price (because 75/100 = 75%).



You saved $25.

The discount is 25% of the regular price (because 25/100 = 25%).