All GMAT Math Resources
Example Questions
Example Question #18 :Dsq: Solving Inequalities
is a real number. True or false:is positive.
Statement 1:
Statement 2:
STATEMENT 1 ALONE provides sufficient information to answer the question, but STATEMENT 2 ALONE does NOT provide sufficient information to answer the question.
BOTH STATEMENTS TOGETHER do NOT provide sufficient information to answer the question.
STATEMENT 2 ALONE provides sufficient information to answer the question, but STATEMENT 1 ALONE does NOT provide sufficient information to answer the question.
BOTH STATEMENTS TOGETHER provide sufficient information to answer the question, but NEITHER STATEMENT ALONE provides sufficient information to answer the question.
EITHER STATEMENT ALONE provides sufficient information to answer the question.
EITHER STATEMENT ALONE provides sufficient information to answer the question.
Assume Statement 1 alone. Ifis positive, thenand; sinceis the sum of three positive numbers, then, andis a false statement. Therefore,cannot be positive.
Assume Statement 2. Ifis positive, then so is, and the inequality can be rewritten as
Consequently,
,
a contradiction sinceis positive. Therefore,is not positive.
Example Question #19 :Dsq: Solving Inequalities
is a real number. True or false:is positive.
Statement 1:
Statement 2:
EITHER STATEMENT ALONE provides sufficient information to answer the question.
BOTH STATEMENTS TOGETHER provide sufficient information to answer the question, but NEITHER STATEMENT ALONE provides sufficient information to answer the question.
STATEMENT 2 ALONE provides sufficient information to answer the question, but STATEMENT 1 ALONE does NOT provide sufficient information to answer the question.
STATEMENT 1 ALONE provides sufficient information to answer the question, but STATEMENT 2 ALONE does NOT provide sufficient information to answer the question.
BOTH STATEMENTS TOGETHER do NOT provide sufficient information to answer the question.
STATEMENT 1 ALONE provides sufficient information to answer the question, but STATEMENT 2 ALONE does NOT provide sufficient information to answer the question.
Assume Statement 1 alone., or. For any base, if, then, so it follows that.is therefore positive.
Assume Statement 2 alone. Bothandare solutions:
and
The sign ofcannot be determined.
Example Question #1 :Dsq: Understanding Functions
Define.
Evaluate.
Statement 1:
Statement 2:
Statement 1 ALONE is sufficient to answer the question, but Statement 2 ALONE is NOT sufficient to answer the question.
EITHER statement ALONE is sufficient to answer the question.
Statement 2 ALONE is sufficient to answer the question, but Statement 1 ALONE is NOT sufficient to answer the question.
BOTH statements TOGETHER are sufficient to answer the question, but NEITHER statement ALONE is sufficient to answer the question.
BOTH statements TOGETHER are insufficient to answer the question.
Statement 1 ALONE is sufficient to answer the question, but Statement 2 ALONE is NOT sufficient to answer the question.
If you know that, then you can calculate:
Knowing the-values ofthat arepairedwith-value 9, however, is neither necessary nor useful here.
例子问题# 2:Dsq: Understanding Functions
The first term of an arithmetic sequence is 100. What is the second term?
Statement 1: The sum of the third and fourth terms is 320.
Statement 2: The tenth term subtracted from the twelfth term yields a difference of 48.
BOTH statements TOGETHER are insufficient to answer the question.
BOTH statements TOGETHER are sufficient to answer the question, but NEITHER statement ALONE is sufficient to answer the question.
Statement 2 ALONE is sufficient to answer the question, but Statement 1 ALONE is NOT sufficient to answer the question.
Statement 1 ALONE is sufficient to answer the question, but Statement 2 ALONE is NOT sufficient to answer the question.
EITHER statement ALONE is sufficient to answer the question.
EITHER statement ALONE is sufficient to answer the question.
Letbe the common difference of the sequence. Then the third and fourth terms are, respectively,and. If their sum is 320, then
If the difference between the twelfth termand tenth termis 24, then
From either statement, the common difference can be calculated, then added to 100 to get the second term, 124.
Example Question #3 :Dsq: Understanding Functions
What is the first term of a geometric sequence?
Statement 1: The product of the second and third terms is 4,096.
Statement 2: The product of the first and fourth terms is 4,096.
BOTH statements TOGETHER are sufficient to answer the question, but NEITHER statement ALONE is sufficient to answer the question.
BOTH statements TOGETHER are insufficient to answer the question.
Statement 2 ALONE is sufficient to answer the question, but Statement 1 ALONE is NOT sufficient to answer the question.
EITHER statement ALONE is sufficient to answer the question.
Statement 1 ALONE is sufficient to answer the question, but Statement 2 ALONE is NOT sufficient to answer the question.
BOTH statements TOGETHER are insufficient to answer the question.
Letbe the first term andbe the common ratio. Then the first four terms are:
两个圣atements are equivalent to the equationsand. But they turn out to be equivalent as can be seen here:
This (common) statement alone is not enough to allow us to calculate.
Example Question #4 :Dsq: Understanding Functions
This relation has five different ordered pairs: is it a function?
Statement 1:
Statement 2:
Statement 1 ALONE is sufficient to answer the question, but Statement 2 ALONE is NOT sufficient to answer the question.
Statement 2 ALONE is sufficient to answer the question, but Statement 1 ALONE is NOT sufficient to answer the question.
BOTH statements TOGETHER are sufficient to answer the question, but NEITHER statement ALONE is sufficient to answer the question.
EITHER statement ALONE is sufficient to answer the question.
BOTH statements TOGETHER are insufficient to answer the question.
Statement 2 ALONE is sufficient to answer the question, but Statement 1 ALONE is NOT sufficient to answer the question.
To prove that a relation is a function, you must prove that no-coordinate is matched with more than one-coordinate. Statement 2 proves that this is false, since 5 is now matched with bothand, which are different numbers regardless of. Statement 1 is irrelevant, since it does not prove or disprove this condition.
Example Question #5 :Dsq: Understanding Functions
Evaluate.
Statement 1: The graph ofincludes the point.
Statement 2:
Statement 1 ALONE is sufficient to answer the question, but Statement 2 ALONE is NOT sufficient to answer the question.
EITHER statement ALONE is sufficient to answer the question.
Statement 2 ALONE is sufficient to answer the question, but Statement 1 ALONE is NOT sufficient to answer the question.
BOTH statements TOGETHER are insufficient to answer the question.
BOTH statements TOGETHER are sufficient to answer the question, but NEITHER statement ALONE is sufficient to answer the question.
Statement 1 ALONE is sufficient to answer the question, but Statement 2 ALONE is NOT sufficient to answer the question.
If, then, so this question is equivalent to evaluating.
If the ordered pairis on the graph of, then, so.
Knowing thatis of no help, as this just tells us.
Example Question #6 :Dsq: Understanding Functions
What is the first term of the geometric sequence?
Statement 1: The sum of the second and third terms is 90.
Statement 2: The sum of the third and fourth terms is 450.
Statement 2 ALONE is sufficient to answer the question, but Statement 1 ALONE is NOT sufficient to answer the question.
Statement 1 ALONE is sufficient to answer the question, but Statement 2 ALONE is NOT sufficient to answer the question.
BOTH statements TOGETHER are insufficient to answer the question.
EITHER statement ALONE is sufficient to answer the question.
BOTH statements TOGETHER are sufficient to answer the question, but NEITHER statement ALONE is sufficient to answer the question.
BOTH statements TOGETHER are sufficient to answer the question, but NEITHER statement ALONE is sufficient to answer the question.
Letbe the first term andbe the common ratio. Then the first four terms are:
.
两个圣atements below are equivalent toand, respectively. Neither, alone, will help you figure outor. If you know both, you can use algebra to deduce their values:
Divide both sides of the first equation by both sides of the second:
Substitute this value into either equation. We'll use the 2nd equation:
Example Question #7 :Dsq: Understanding Functions
is defined to be the greatest integer less than or equal to.
Evaluate
Statement 1:
Statement 2:
BOTH statements TOGETHER are insufficient to answer the question.
EITHER statement ALONE is sufficient to answer the question.
Statement 1 ALONE is sufficient to answer the question, but Statement 2 ALONE is NOT sufficient to answer the question.
BOTH statements TOGETHER are sufficient to answer the question, but NEITHER statement ALONE is sufficient to answer the question.
Statement 2 ALONE is sufficient to answer the question, but Statement 1 ALONE is NOT sufficient to answer the question.
Statement 2 ALONE is sufficient to answer the question, but Statement 1 ALONE is NOT sufficient to answer the question.
Statement 1 is not enough to answer this question.
Case 1:
Then
Case 2:
Then
If Statement 2 is true, however:
Example Question #8 :Dsq: Understanding Functions
This relation has the following five ordered pairs: is it a function?
Statement 1:
Statement 2:
EITHER statement ALONE is sufficient to answer the question.
Statement 2 ALONE is sufficient to answer the question, but Statement 1 ALONE is NOT sufficient to answer the question.
Statement 1 ALONE is sufficient to answer the question, but Statement 2 ALONE is NOT sufficient to answer the question.
BOTH statements TOGETHER are sufficient to answer the question, but NEITHER statement ALONE is sufficient to answer the question.
BOTH statements TOGETHER are insufficient to answer the question.
Statement 1 ALONE is sufficient to answer the question, but Statement 2 ALONE is NOT sufficient to answer the question.
To prove that a relation is a function, you must prove that no-coordinate is matched with more than one-coordinate. Statement 1 proves that this is true. Statement 2 is irrelevant; it is possible for more than one-coordinate to be matched with the same-coordinate in a function.