Ask Me Help Desk

Ask Me Help Desk (https://www.askmehelpdesk.com/forum.php)
-   Math & Sciences (https://www.askmehelpdesk.com/forumdisplay.php?f=402)
-   -   Percentage (https://www.askmehelpdesk.com/showthread.php?t=396797)

  • Sep 15, 2009, 11:47 PM
    ryo23
    Percentage
    We need help with this problem. Let's go with the number 20 and if we add 5% the answer will be 21. OK But if we subtract 5% of 21 the answer is 19.55. Our question is how can we get back to the #20?

    It might be a simple answer but we need help. Is there a formula?

    VERY Confused!! :confused::confused::confused:
  • Sep 16, 2009, 06:28 AM
    ArcSine
    If u represents the percentage you originally added to the starting number (5%, in your example), then



    is the percentage you'd need to deduct from the intermediate amount to get back to your original starting number.

    For example, if you start by adding 25% to some starting number, then (by that formula) you'll get back to the starting number by deducting 20% from the intermediate amount.

    Of course, re-express your percentage into decimal form when using the formula; i.e. u = 0.05 in your example.

    Hope that helps out a bit.

  • All times are GMT -7. The time now is 10:40 PM.