Andrew decreased his hourly rate by 25% to accommodate more clients. However, he realized that his rate was too low and decided to revert to his original hourly rates. By what percent must Andrew now increase his current rate to bring it back to its original amount?

Incorrect.
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This is exactly what GMAC wants you to think. Pay attention—what is the original whenever you work with percents?

Correct.
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__Plug In__ 100 for Andrew's hourly rate (the invisible variable). A 25% decrease brings his rate down to $$100-25=75$$. In order to revert to the initial rate, Andrew needs to increase his rate by 25. Use the percent change formula:
>$$\displaystyle \text{Percent change} =\frac{\text{Difference}}{\text{Original}} \times 100$$.
Thus, to go up from 75 to 100, the percent change is
>$$\displaystyle \text{Percent change} =\frac{25}{75}\times 100=33.3\%$$.

Incorrect.
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Incorrect.
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Incorrect.
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25%

33.3%

50%

66.7%

75%