All GMAT Math Resources
Example Questions
Example Question #11 : Dsq: Understanding Absolute Value
Of distinct integers , which is the greatest of the three?
Statement 1:
Statement 2:
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.
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.
The two statements together are insufficient.
For example, let . Then, from Statement 2,
Therefore, either or
.
In either case, Statement 2 is shown to be true, since
and
But if , then
is the greatest of the three. If
, then
is the greatest. Therefore,the two statements together are not enough.
Example Question #11 : Dsq: Understanding Absolute Value
Of distinct integers , which is the greatest of the three?
Statement 1:
Statement 2: and
are negative.
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.
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 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 gives insufficient information.
Case 1:
, which is true.
Case 2:
, which is true.
But in the first case, is the greatest of the three. In the second,
is the greatest.
Statement 2 gives insuffcient information, since no information is given about the sign of .
Assume both statements to be true. , and from Statement 1,
; by transitivity,
. From Statement 2,
. This makes
the greatest of the three.
Example Question #13 : Dsq: Understanding Absolute Value
Let be any three (not necessarily distinct) integers.
At how many points does the graph of the function
intersect the -axis?
Statement 1: and
are nonzero integers of opposite sign.
Statement 2: and
are nonzero integers of opposite sign.
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.
BOTH statements TOGETHER are sufficient to answer the question, but NEITHER statement ALONE is sufficient to answer the question.
To determine the point(s), if any, at which the graph of a function intersects the
-axis, set
and solve for
.
At this point, we can examine the equation. Since the absolute value of a number must be nonnegative, the sign of tells us how many solutions exist to this equation. If
, there is no solution, and therefore, the graph of
does not intersect the
-axis. If
, then there is one solution, and, therefore, the graph of
intersects the
-axis at exactly one point. If
, then there are two solutions, and, therefore, the graph of
intersects the
-axis at exactly two points.
To determine the sign of , we need to whether the signs of both
and
are like or unlike, or that
. Either statement alone eliminates the possibility that
, but neither alone gives the signs of both
and
. However, if both statements are assumed, then, since
and
have the opposite sign as
, they have the same sign. This makes
and
, so the graph of
can be determined to not cross the
-axis at all.
Example Question #181 : Algebra
Which, if either, is the greater number: or
?
Statement 1:
Statement 2:
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.
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.
Statement 2 ALONE is sufficient to answer the question, but Statement 1 ALONE is NOT sufficient to answer the question.
Statement 1 alone gives insufficient information, as is seen in these two cases:. For example, if , then
However, if , then
Therefore, it is not clear which, if either, of and
is greater.
Now assume Statement 2 alone.
If is negative, then
, which, being an absolute value of a number, must be nonnegative, is the greater number. If
is positive, then so is
, so
.
Therefore,
.
is the greater number in either case.
Example Question #11 : Dsq: Understanding Absolute Value
Let be any three (not necessarily distinct) integers.
At how many points does the graph of the function
intersect the -axis?
Statement 1:
Statement 2:
EITHER statement ALONE is 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.
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.
To determine the point(s), if any, at which the graph of a function intersects the
-axis, set
and solve for
.
At this point, we can examine the equation. For a solution to exist, since the absolute value of a number must be nonnegative, it must hold that . This happens if
and
are of opposite sign, or if
. However, Statement 2 tells us that
, and neither statement tells us the sign of
. The two statements together provide insufficient information.
All GMAT Math Resources
