Don’t lose your progress!

We cover every section of the GMAT with in-depth lessons, 5000+ practice questions and realistic practice tests.

Up to 90+ points GMAT score improvement guarantee

The best guarantee you’ll find

Our Premium and Ultimate plans guarantee up to 90+ points score increase or your money back.

Master each section of the test

Comprehensive GMAT prep

We cover every section of the GMAT with in-depth lessons, 5000+ practice questions and realistic practice tests.

Schedule-free studying

Learn on the go

Study whenever and wherever you want with our iOS and Android mobile apps.

The most effective way to study

Personalized GMAT prep, just for you!

Adaptive learning technology focuses on your academic weaknesses.

Percents: Percent Change

Aaron's accountant accidentally decreased the salary of an employee by 25% instead of giving her a 25% increase. After receiving her paycheck, the employee complained to Aaron. The accountant was asked to fix the mistake by giving the employee a check for the missing amount. The make-up check is approximately what percent of the erroneous paycheck?
Incorrect. [[snippet]] __Plug In__ 100 for the employee's salary (the invisible variable) to demonstrate that if you decrease it by 25% ($$100-25=75$$), then an 80% check on 75 will be 60 ($$75\cdot 0.8 = 60$$). The employee's paycheck should have been $$100+25 = 125$$. A check of 60 would be too much.
Correct. [[snippet]] __Plug In__ 100 for the employee's original salary (the invisible variable). After the accidental decrease of 25%, the employee's salary becomes $$100-25=75$$. The intended increase in the employee's salary should have resulted in $$100+25=125$$. To fix that, the accountant needs to give the employee a check for 50. Use the percent change formula: >$$\displaystyle \text{Percent change}=\frac{\text{Difference}}{\text{Original}} \times 100$$. Pay attention to the original. >$$\displaystyle \text{Percent change} = \frac{50}{75}\times 100 \approx 66.7\%$$. Therefore, the additional check (50) is 66.7% of the short paycheck (75). Thus, the correct answer is 67%.
Incorrect. [[snippet]] __Plug In__ 100 for the employee's initial salary. While it's true that $$\left(\frac{125-75}{\bf{100}}\right)\times 100 = 50\%$$, the question does not ask for the percent of the employee's _initial_ salary. It asks for the percent of the _short_ paycheck.
Incorrect. [[snippet]] __Plug In__ 100 for the employee's salary (the invisible variable) to demonstrate that if you decrease it by 25% ($$100-25=75$$), then a 33% check on 75 will only be about 25 ($$75\cdot 0.33 = 24.75$$). This will just get the employee back to her original salary, but her salary should have increased.
Incorrect. [[snippet]] __Plug In__ 100 for the employee's salary (the invisible variable) to demonstrate that if you decrease it by 25% ($$100-25=75$$), then a 20% check on 75 will only be 15 ($$75\cdot 0.2 = 15$$). This won't even get the employee back to her original salary—not to mention her increased salary.
20%
33%
50%
67%
80%