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Sales tax formula

  1. Feb 2, 2008 #1
    Hi everyone,

    1. The problem statement, all variables and given/known data
    A child is surprised that she must pay $1.40 for a toy marked $1.25 because of sales tax. What is the effective tax rate on this purchase?

    2. Relevant equations

    3. The attempt at a solution

    I know that the difference between the two is .15. I could just guess and check, but is there a formula?

    Thank you very much
  2. jcsd
  3. Feb 2, 2008 #2
    Try thinking about how tax is computed.

    1.25 * r = 0.15
  4. Feb 2, 2008 #3
    Thank you very much

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