All GRE Math Resources
Example Questions
Example Question #7 : How To Find The Solution To An Inequality With Division
What is the solution set of the inequality ?
We simplify this inequality similarly to how we would simplify an equation
Thus
Example Question #4 : Inequalities
What is a solution set of the inequality ?
In order to find the solution set, we solve as we would an equation:
Therefore, the solution set is any value of .
Example Question #3 : How To Find The Solution To An Inequality With Division
Quantity A:
The smallest possible value for
Quantity B:
The smallest possible value for
Which of the following is true?
A comparison cannot be detemined from the given information.
The two quantities are equal.
Quantity B is larger.
Quantity A is larger.
Quantity A is larger.
Recall that when you have an absolute value and an inequality like
,
this is the same as saying that must be between and . You can rewrite it:
To solve this, you just apply your modifications to each and every part of the inequality.
First, subtract :
Then, divide by :
Next, do the same for the other equation.
becomes...
Then, subtract :
Then, divide by :
Thus, the smallest value for is , while the smallest value for is . Therefore, quantity A is greater.
Example Question #2 : Inequalities
The cost, in cents, of manufacturing pencils is , where 1200 is the number of cents required to run the factory regardless of the number of pencils made, and 20 represents the per-unit cost, in cents, of making each pencil. The pencils sell for 50 cents each. What number of pencils would need to be sold so that the revenue received is at least equal to the manufacturing cost?
If each pencil sells at 50 cents, pencils will sell at . The smallest value of such that
Example Question #1 : How To Find The Solution To An Inequality With Subtraction
Find the slope of the inequality equation
–1
1
7
–7
0
–1
The answer is:
From the equation we can see that the slope is –1.
Example Question #11 : Inequalities
and are both integers.
If , , and , which of the following is a possible value of ?
Take the values of y that are possible, i.e. 2 and 3, and plug them into the first inequality. First, plug in 2. 2 – 3x > 21. Subtract 2 from both sides, and then divide by –3. Don't forget that when you divide or multiply by a negative number in an inequality you must flip the inequality sign. Thus, x < –19/3. Now plug in 3. We find, following the same steps, that when y=3, x < –6. Thus –7 is the correct answer.
Example Question #213 : Gre Quantitative Reasoning
Quantity A:
The value(s) for which the following function is undefined:
Quantity B:
Which of the following is true?
The two quantities are equal.
Quantity A is larger.
A comparison cannot be detemined from the given information.
Quantity B is larger.
Quantity B is larger.
This question is not as hard as it seems. Remember that for real numbers, square roots cannot be taken of negative numbers. Therefore, we know that this function is undefined for:
This is simple to solve. Merely add to both sides:
Then, divide by :
Therefore, quantity A is less than quantity B. This means that quantity B is greater than it.
Example Question #214 : Gre Quantitative Reasoning
Quantity A:
Quantity B:
Which of the following is true?
Quantity A is larger.
Quantity B is larger.
A comparison cannot be detemined from the given information.
The two quantities are equal.
A comparison cannot be detemined from the given information.
Recall that when you have an absolute value and an inequality like
,
this is the same as saying that must be between and . You can rewrite it:
To solve this, you merely need to subtract from all three values:
Since is between and , it could be both larger or smaller than . Therefore, you cannot determine the relationship based on the given information.
Example Question #171 : Equations / Inequalities
Quantitative Comparison
Column A:
Column B:
The quantities are equal.
Quantity A is greater.
The relationship cannot be determined from the information provided.
Quantity B is greater.
The relationship cannot be determined from the information provided.
For quantitative comparison questions involving a shared variable between quantities, the best approach is to test a positive integer, a negative integer, and a fraction. Half of our work is eliminated, however, because the question stipulates that x > 0. We only need to check a positive integer and a positive fraction between 0 and 1. Plugging in 2, we see that quantity A is greater than quantity B. Checking 1/2, however, we find that quantity B is greater than quantity A. Thus the relationship cannot be determined.
Example Question #221 : Gre Quantitative Reasoning
If –1 < n < 1, all of the following could be true EXCEPT:
16n2 - 1 = 0
n2 < n
n2 < 2n
|n2 - 1| > 1
(n-1)2 > n
|n2 - 1| > 1