Multiple Choice (Single Answer) Strategy - GRE Quantitative Reasoning
Card 1 of 25
What should you do if two different plug-in tests give different answer choices?
What should you do if two different plug-in tests give different answer choices?
Tap to reveal answer
Recheck restrictions; otherwise the method was applied incorrectly. Inconsistencies indicate errors in value selection or application, requiring verification.
Recheck restrictions; otherwise the method was applied incorrectly. Inconsistencies indicate errors in value selection or application, requiring verification.
← Didn't Know|Knew It →
What is the most common error when plugging in numbers for variables?
What is the most common error when plugging in numbers for variables?
Tap to reveal answer
Choosing values that violate a restriction (such as $x \neq 0$). Invalid values lead to incorrect evaluations by breaching problem constraints.
Choosing values that violate a restriction (such as $x \neq 0$). Invalid values lead to incorrect evaluations by breaching problem constraints.
← Didn't Know|Knew It →
What is the main rule for picking numbers when using “plugging in” with variables?
What is the main rule for picking numbers when using “plugging in” with variables?
Tap to reveal answer
Choose simple values that satisfy all stated restrictions. Valid numbers ensure the substitution respects the problem's conditions for accurate results.
Choose simple values that satisfy all stated restrictions. Valid numbers ensure the substitution respects the problem's conditions for accurate results.
← Didn't Know|Knew It →
What is the best first step in a multiple-choice single-answer problem before calculating?
What is the best first step in a multiple-choice single-answer problem before calculating?
Tap to reveal answer
Identify what is asked and restate the target quantity. Clarifies the goal, preventing misinterpretation and guiding efficient problem-solving.
Identify what is asked and restate the target quantity. Clarifies the goal, preventing misinterpretation and guiding efficient problem-solving.
← Didn't Know|Knew It →
Which strategy is best when the answer choices are widely spaced and computation is messy?
Which strategy is best when the answer choices are widely spaced and computation is messy?
Tap to reveal answer
Estimate to eliminate choices, then compute only if needed. Approximation narrows options quickly, saving time on complex calculations.
Estimate to eliminate choices, then compute only if needed. Approximation narrows options quickly, saving time on complex calculations.
← Didn't Know|Knew It →
What is the fastest method when the question asks for a value and choices are numeric?
What is the fastest method when the question asks for a value and choices are numeric?
Tap to reveal answer
Work forward to the value and match it to one choice. Direct computation yields the exact value for matching against provided numeric options.
Work forward to the value and match it to one choice. Direct computation yields the exact value for matching against provided numeric options.
← Didn't Know|Knew It →
Which method is best when the choices are expressions in $x$ and the prompt gives constraints on $x$?
Which method is best when the choices are expressions in $x$ and the prompt gives constraints on $x$?
Tap to reveal answer
Plug in convenient values that satisfy the constraints. Substitution simplifies evaluating expressions under given constraints to identify the correct one.
Plug in convenient values that satisfy the constraints. Substitution simplifies evaluating expressions under given constraints to identify the correct one.
← Didn't Know|Knew It →
What is “backsolving” in multiple-choice single-answer quantitative questions?
What is “backsolving” in multiple-choice single-answer quantitative questions?
Tap to reveal answer
Test answer choices in the prompt until one works. Involves substituting choices into the problem to find which satisfies the conditions.
Test answer choices in the prompt until one works. Involves substituting choices into the problem to find which satisfies the conditions.
← Didn't Know|Knew It →
Which answer choice should you test first when backsolving and choices are ordered?
Which answer choice should you test first when backsolving and choices are ordered?
Tap to reveal answer
Choice $C$, then move up or down based on the result. Starting centrally allows efficient adjustment based on whether the result is too high or low.
Choice $C$, then move up or down based on the result. Starting centrally allows efficient adjustment based on whether the result is too high or low.
← Didn't Know|Knew It →
Which option is the value of $\frac{9}{3} \times \frac{2}{3}$: $1$, $2$, $3$, or $4$?
Which option is the value of $\frac{9}{3} \times \frac{2}{3}$: $1$, $2$, $3$, or $4$?
Tap to reveal answer
$2$. Simplifying fractions first gives $3 imes rac{2}{3}$, which equals $2$.
$2$. Simplifying fractions first gives $3 imes rac{2}{3}$, which equals $2$.
← Didn't Know|Knew It →
Which option is the value of $5!$: $20$, $60$, $100$, or $120$?
Which option is the value of $5!$: $20$, $60$, $100$, or $120$?
Tap to reveal answer
$120$. Factorial of $5$ multiplies integers from $1$ to $5$, equaling $120$.
$120$. Factorial of $5$ multiplies integers from $1$ to $5$, equaling $120$.
← Didn't Know|Knew It →
Which option is the value of $\frac{7}{8}$ as a decimal: $0.78$, $0.875$, $0.70$, or $1.14$?
Which option is the value of $\frac{7}{8}$ as a decimal: $0.78$, $0.875$, $0.70$, or $1.14$?
Tap to reveal answer
$0.875$. Dividing $7$ by $8$ produces the repeating decimal $0.875$.
$0.875$. Dividing $7$ by $8$ produces the repeating decimal $0.875$.
← Didn't Know|Knew It →
Which option is the solution to $3x = 18$: $3$, $6$, $9$, or $12$?
Which option is the solution to $3x = 18$: $3$, $6$, $9$, or $12$?
Tap to reveal answer
$6$. Dividing both sides by $3$ isolates $x$ to satisfy the equation.
$6$. Dividing both sides by $3$ isolates $x$ to satisfy the equation.
← Didn't Know|Knew It →
Which option is the value of $\left| -7 + 2 \right|$: $-5$, $5$, $9$, or $-9$?
Which option is the value of $\left| -7 + 2 \right|$: $-5$, $5$, $9$, or $-9$?
Tap to reveal answer
$5$. Absolute value of $-5$ yields the positive distance from zero.
$5$. Absolute value of $-5$ yields the positive distance from zero.
← Didn't Know|Knew It →
Which option is the value of $\frac{2}{5} + \frac{1}{10}$: $\frac{1}{2}$, $\frac{3}{10}$, $\frac{1}{5}$, or $\frac{9}{10}$?
Which option is the value of $\frac{2}{5} + \frac{1}{10}$: $\frac{1}{2}$, $\frac{3}{10}$, $\frac{1}{5}$, or $\frac{9}{10}$?
Tap to reveal answer
$\frac{1}{2}$. Common denominator of $10$ converts fractions, summing to $ rac{5}{10}$ or $ rac{1}{2}$.
$\frac{1}{2}$. Common denominator of $10$ converts fractions, summing to $ rac{5}{10}$ or $ rac{1}{2}$.
← Didn't Know|Knew It →
Which option equals $\frac{1}{3}$ of $90$: $15$, $20$, $30$, or $45$?
Which option equals $\frac{1}{3}$ of $90$: $15$, $20$, $30$, or $45$?
Tap to reveal answer
$30$. Dividing $90$ by $3$ directly computes one-third of the value.
$30$. Dividing $90$ by $3$ directly computes one-third of the value.
← Didn't Know|Knew It →
Which option is equal to $2^5$: $10$, $16$, $32$, or $64$?
Which option is equal to $2^5$: $10$, $16$, $32$, or $64$?
Tap to reveal answer
$32$. Raising $2$ to the fifth power multiplies $2$ five times, resulting in $32$.
$32$. Raising $2$ to the fifth power multiplies $2$ five times, resulting in $32$.
← Didn't Know|Knew It →
What is a key warning sign that you should try plugging in numbers instead of algebra?
What is a key warning sign that you should try plugging in numbers instead of algebra?
Tap to reveal answer
The problem has variables but no specific values given. Variables without values suggest numerical substitution can simplify algebraic manipulation.
The problem has variables but no specific values given. Variables without values suggest numerical substitution can simplify algebraic manipulation.
← Didn't Know|Knew It →
Which option is closest to $\sqrt{50}$: $5$, $7$, $10$, or $25$?
Which option is closest to $\sqrt{50}$: $5$, $7$, $10$, or $25$?
Tap to reveal answer
$7$. Since $sqrt{49}=7$ and $sqrt{50}$ is slightly more, $7$ is the closest integer.
$7$. Since $sqrt{49}=7$ and $sqrt{50}$ is slightly more, $7$ is the closest integer.
← Didn't Know|Knew It →
Which option equals $\frac{3}{4}$: $0.34$, $0.75$, $\frac{4}{3}$, or $\frac{3}{8}$?
Which option equals $\frac{3}{4}$: $0.34$, $0.75$, $\frac{4}{3}$, or $\frac{3}{8}$?
Tap to reveal answer
$0.75$. Dividing $3$ by $4$ yields $0.75$ as the decimal equivalent.
$0.75$. Dividing $3$ by $4$ yields $0.75$ as the decimal equivalent.
← Didn't Know|Knew It →
What is the fastest check after you select a final answer choice?
What is the fastest check after you select a final answer choice?
Tap to reveal answer
Substitute it back and verify it satisfies the question. Substitution confirms the choice meets all problem conditions accurately.
Substitute it back and verify it satisfies the question. Substitution confirms the choice meets all problem conditions accurately.
← Didn't Know|Knew It →
What is the best practice when the question asks for a ratio or fraction result?
What is the best practice when the question asks for a ratio or fraction result?
Tap to reveal answer
Keep values as fractions to avoid rounding errors. Fractions maintain precision, ensuring the exact ratio without decimal approximations.
Keep values as fractions to avoid rounding errors. Fractions maintain precision, ensuring the exact ratio without decimal approximations.
← Didn't Know|Knew It →
What is the elimination rule if an answer choice makes a square root of a negative number in reals?
What is the elimination rule if an answer choice makes a square root of a negative number in reals?
Tap to reveal answer
Eliminate it; it is not a real-valued solution. Square roots of negatives are not real, disqualifying the choice in real number contexts.
Eliminate it; it is not a real-valued solution. Square roots of negatives are not real, disqualifying the choice in real number contexts.
← Didn't Know|Knew It →
What is the elimination rule if an answer choice makes a denominator $0$ in the original problem?
What is the elimination rule if an answer choice makes a denominator $0$ in the original problem?
Tap to reveal answer
Eliminate it; it is invalid for the original expression. Division by zero renders the expression undefined, invalidating the choice.
Eliminate it; it is invalid for the original expression. Division by zero renders the expression undefined, invalidating the choice.
← Didn't Know|Knew It →
Which approach is best when the choices are close together and exactness matters?
Which approach is best when the choices are close together and exactness matters?
Tap to reveal answer
Compute exactly rather than estimating. Precise calculation distinguishes between similar options where approximation fails.
Compute exactly rather than estimating. Precise calculation distinguishes between similar options where approximation fails.
← Didn't Know|Knew It →