Master the GRE with Official-Calibrated Questions

Q: How do the adaptive mock exams and daily quizzes work?

Daily quizzes deliver 20 balanced questions (10 Quantitative, 10 Verbal) calibrated to official ETS standards with step-by-step KaTeX mathematical proofs. Full diagnostic mock exams feature true Section-Level Adaptivity (SLA)—routing Section 2 difficulty based on your Section 1 performance—and LLM-based 6-point Analytical Writing rubric essay grading.

Q: What practice modes are available on MockTestBank?

Students can train with daily 20-question timed sets, targeted topic drills (like Arithmetic, Geometry, Text Completion, or Reading Comprehension), full-length computer-adaptive diagnostic mock exams, and personalized error pool reviews.

Question 1

Question 1 Quantitative arithmetic

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The price of a collectible antique was increased by

25\%

and then during a holiday promotion, the new price was discounted by

20\%

. If the final sale price was

\$600

, what was the original price before either change?

Answer

Correct Answer:

\$600

Step-by-Step Proof:

Let the original price be

P

. 1. An increase of

25\%

multiplies the price by

(1 + 0.25) = 1.25 = \frac{5}{4}

. 2. A subsequent discount of

20\%

multiplies that intermediate price by

(1 - 0.20) = 0.80 = \frac{4}{5}

. 3. Set up the cumulative multiplication:

\text{Final Price} = P \times \frac{5}{4} \times \frac{4}{5} = P \times 1 = P

Because the net multiplier is exactly

1

, the final price equals the original price. Hence,

P = \$600

.

Common ETS Trap Warning:

Examinees often falsely believe that

+25\%

followed by

-20\%

results in a net increase of

5\%

. Because percent changes apply successively to changing bases,

+25\%

followed by

-20\%

nets exactly

0\%

.

🎯 Key Rule:

Always convert successive percentage changes into multiplying factors:

(1 + r_1)(1 - r_2)

.

Practice More arithmetic Drills →

Question 2

Question 2 Quantitative algebra

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In the

xy

-coordinate plane, line

L_1

passes through the points

(2, 3)

and

(6, 11)

. Line

L_2

is perpendicular to

L_1

and passes through the point

(4, -1)

. What is the

y

-intercept of line

L_2

?

Answer

Correct Answer:

1

Step-by-Step Proof:

1. Find the slope of line

L_1

:

m_1 = \frac{11 - 3}{6 - 2} = \frac{8}{4} = 2

2. Since

L_2 \perp L_1

, its slope

m_2

is the negative reciprocal:

m_2 = -\frac{1}{m_1} = -\frac{1}{2}

3. Use point-slope form with

(4, -1)

:

y - (-1) = -\frac{1}{2}(x - 4)

y + 1 = -\frac{1}{2}x + 2 \implies y = -\frac{1}{2}x + 1

4. The

y

-intercept (

b

) is

1

.

🎯 Key Rule:

Perpendicular lines have negative reciprocal slopes:

m_1 \cdot m_2 = -1

.

Practice More algebra Drills →

Question 3

Question 3 Quantitative data analysis

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A university research committee of

4

members is to be selected from a pool of

5

chemists and

4

biologists. If the committee must contain at least

1

biologist, how many distinct committees can be formed?

Answer

Correct Answer:

121

Step-by-Step Proof:

Use the complement principle (Total

-

Unwanted): 1. Total ways to select any

4

members from the total pool of

5 + 4 = 9

scientists:

\binom{9}{4} = \frac{9 \times 8 \times 7 \times 6}{4 \times 3 \times 2 \times 1} = 126

2. Unwanted scenario: committees with ZERO biologists (all

4

members chosen exclusively from the

5

chemists):

\binom{5}{4} = 5

3. Subtract the unwanted from the total:

\text{Committees with at least 1 biologist} = 126 - 5 = 121

Common ETS Trap Warning:

Examinees who calculate by cases (1 bio + 2 bio + 3 bio + 4 bio) often make arithmetic errors or inadvertently double-count committees by selecting "1 biologist first, then 3 remaining". The complement method is airtight.

🎯 Key Rule:

For "at least one" counting problems, always use:

\text{Total} - \text{None}

.

Practice More data analysis Drills →

Question 4

Question 4 Verbal critical reasoning

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A municipal health department reported that residents who regularly consume green tea have a

30\%

lower incidence of coronary artery disease than those who do not. The health director concluded that antioxidant polyphenols found in green tea provide direct cardiovascular protection and proposed subsidizing green tea purchases across public supermarkets. Which of the following, if true, most seriously calls into question the health director’s recommendation?

Answer

Correct Answer: Individuals who regularly drink green tea are significantly more likely to engage in regular aerobic exercise and adhere to low-sodium diets than non-drinkers.

Step-by-Step Proof:

1. Deconstruct the argument: - Premise: Green tea drinkers have

30\%

lower incidence of coronary disease. - Conclusion: Green tea polyphenols directly provide the cardiovascular protection. 2. Flaw in reasoning: Correlation does not equal causation! The argument fails to consider a confounding third variable (healthy user bias). 3. Weakener evaluation: - Choice B presents the classic confounding variable: green tea drinkers also exercise more and eat healthier diets. These lifestyle factors, rather than the green tea itself, could entirely explain the lower heart disease rates! Choices A, C, D, and E are irrelevant to whether green tea was the causal agent of the cardiac benefits.

Common ETS Trap Warning:

Correlation-to-causation is the #1 Critical Reasoning trap on the GRE. The correct weakener points directly to an unobserved confounding factor that accounts for the observed correlation.

🎯 Key Rule:

When an argument infers causation from a statistical correlation, look for a third variable (confounder) that causes both.

Practice More critical reasoning Drills →

Question 5

Question 5 Verbal reading comprehension

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Reading Passage: For decades, evolutionary biologists hypothesized that bright avian plumage evolved exclusively through intersexual selection—specifically, female mate preference for vibrant ornamentation. However, recent empirical field studies on tropical tanagers reveal that female individuals frequently display equally brilliant coloration, which serves primarily to defend foraging territories against conspecific rivals. These observations indicate that social competition for limited ecological resources, rather than sexual selection alone, has driven plumage diversification across numerous avian lineages.

The primary purpose of the passage is to:

Answer

Correct Answer: Propose an ecological mechanism that expands traditional explanations of avian coloration.

Step-by-Step Proof:

The author opens with a traditional hypothesis (intersexual selection alone), introduces new evidence (tropical tanagers where females use plumage for territory defense), and concludes that social competition for ecological resources is an additional, critical driver. Choice B accurately captures this nuanced expansion without employing extreme rhetoric. Choices A, D, and E commit the classic ETS "extreme language trap" (e.g. "refute foundational premises", "plays no meaningful role", "complete moratorium"). Choice C misrepresents the passage.

🎯 Key Rule:

ETS Reading Comprehension favors moderate, defensive academic verbs ("expands", "suggests", "qualifies") over sweeping absolutes ("refutes", "proves").

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Master the GRE with Official-Calibrated Questions

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