How do you find the answer of an interest for math? - Answers

For example:say the cost of the pillow is 20 dollars and including 10% interest. How much money did you have to pay?first, you have to change 10% into a decimal, which would be .10then, you multiply .10 with 20. then you would get 2.2 dollars would be the interest.and to see how much you would pay for the pillow including interest, just add 20 dollars to your 2 dolllars.and so you would pay 22 dollars all together.Another example:Say you see something that you know was purchased for $32.30 and the original cost was $38.00 and you want to know what percentage the discount was.If you divide the $32.30 by $38.00, you will get .85. You then subtract that from 1.00 (which represents the 100%), and it will give you .15, or 15%.