Percents are a high-frequency topic on the GRE Quant section. While the calculator is available, top scores come from using smart, efficient methods. This guided path will teach you the core concepts and strategic shortcuts needed for success.
Start with the basics. Practice converting between percents, fractions, and decimals to build a solid foundation.
Convert any fraction to a percentage.
Master the fundamental algebraic skill: solving for the Part, the Percent, or the Whole. This is the engine for all word problems.
"20 is what percent of 50?"
"28 is 40% of what number?"
The GRE loves this concept. See why a +X% and a -X% change don't cancel out, a key insight for Quantitative Comparison questions.
+ 20% and - 20%
= 0% change
$100 → +20% → $120.00
$120.00 → -20% → $96.00
The +20% increase adds $20. The -20% decrease is on the NEW, larger value ($120), so it subtracts $24.00. Result < Start.
Now that you understand the trap, learn the specific formulas required to perfectly reverse an initial percent increase or decrease.
Select a scenario to see the exact percentage needed to return to the original value.
Learn to solve GRE QC questions by focusing on conceptual shortcuts and manipulation instead of slow, brute-force calculation.
Review the most common percent-to-fraction equivalents, then test your memory with an interactive flashcard quiz to boost your calculation speed.
| Percent Change | Multiplier |
|---|---|
| 50% | $$ 1/2 $$ |
| 33.33% | $$ 1/3 $$ |
| 12.5% | $$ 1/8 $$ |
Memorize the direct fractional multipliers for common percent changes to solve problems faster than with a calculator.
| Percent Change | Multiplier |
|---|---|
| 16.66% | $$ 7/6 $$ |
| 20% | $$ 6/5 $$ |
| 25% | $$ 5/4 $$ |
| 33.33% | $$ 4/3 $$ |
| 50% | $$ 3/2 $$ |
| 100% | $$ 2 $$ |
Memorize the multipliers for decreases.
| Percent Change | Multiplier |
|---|---|
| 16.66% | $$ 5/6 $$ |
| 20% | $$ 4/5 $$ |
| 25% | $$ 3/4 $$ |
| 33.33% | $$ 2/3 $$ |
| 50% | $$ 1/2 $$ |
Master the powerful 'a% of b = b% of a' rule to simplify complex calculations like "32% of 50" into easy mental math.
$$ A\% \text{ of } B = B\% \text{ of } A $$
You can flip the numbers to make calculation easier.
Calculate: $$ 32\% \text{ of } 50 $$
Hard to do mentally? Flip it!
$$ 50\% \text{ of } 32 = \frac{1}{2} \times 32 = \mathbf{16} $$
Calculate: $$ 160\% \text{ of } 25 $$
Flip it:
$$ 25\% \text{ of } 160 = \frac{1}{4} \times 160 = \mathbf{40} $$
$$ A\% \times B = \frac{A}{100} \times B = \frac{A \times B}{100} $$
$$ B\% \times A = \frac{B}{100} \times A = \frac{B \times A}{100} $$
Since $$ A \times B = B \times A $$, they are identical.
Put your understanding of GRE Percents: A Guide to Efficient Problem Solving to the test with our premium, adaptive practice questions. Build pacing efficiency and eliminate knowledge gaps now.
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