Problem-Solving Questions - GMAT Quantitative
Card 1 of 16904
Which of the following lines is perpendicular to
?
Which of the following lines is perpendicular to ?
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In order for a line
to be perpendicular to another line
defined by the equation
, the slope of line
must be a negative reciprocal of the slope of line
. Since line
's slope is
in the slope-intercept equation above, line
's slope would therefore be
.
In this instance,
, so
. Therefore, the correct solution is
.
In order for a line to be perpendicular to another line
defined by the equation
, the slope of line
must be a negative reciprocal of the slope of line
. Since line
's slope is
in the slope-intercept equation above, line
's slope would therefore be
.
In this instance, , so
. Therefore, the correct solution is
.
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What is the measurement of an angle that is supplementary to a
angle?
What is the measurement of an angle that is supplementary to a angle?
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Two angles are supplementary if the total of their degree measures is
. Therefore, an angle supplementary to a
angle measures
.
Two angles are supplementary if the total of their degree measures is . Therefore, an angle supplementary to a
angle measures
.
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What is the measure of an angle that is complementary to a
angle?
What is the measure of an angle that is complementary to a angle?
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Two angles are complementary if the total of their degree measures is
. Therefore, an angle complementary to a
angle measures
.
Two angles are complementary if the total of their degree measures is . Therefore, an angle complementary to a
angle measures
.
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Find the equation of the line that is perpendicular to the line connecting the points
.
Find the equation of the line that is perpendicular to the line connecting the points .
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Lines are perpendicular if their slopes are negative reciprocals of each other. First we need to find the slope of the line in the question stem.

The negative reciprocal of 3 is
, so our answer will have a slope of
. Let's go through the answer choices and see.
: This line is of the form
, where
is the slope. The slope is 3, so this line is parallel, not perpendicular, to our line in question.
: The slope here is
, also wrong.
: The slope of this line is
. This is the reciprocal, but not the negative reciprocal, so this is also incorrect.
The line between the points
:
.
This is the correct answer! Let's check the last answer choice as well.
The line between points
:
, which is incorrect.
Lines are perpendicular if their slopes are negative reciprocals of each other. First we need to find the slope of the line in the question stem.
The negative reciprocal of 3 is , so our answer will have a slope of
. Let's go through the answer choices and see.
: This line is of the form
, where
is the slope. The slope is 3, so this line is parallel, not perpendicular, to our line in question.
: The slope here is
, also wrong.
: The slope of this line is
. This is the reciprocal, but not the negative reciprocal, so this is also incorrect.
The line between the points :
.
This is the correct answer! Let's check the last answer choice as well.
The line between points :
, which is incorrect.
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Determine whether the lines with equations
and
are perpendicular.
Determine whether the lines with equations and
are perpendicular.
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If two equations are perpendicular, then they will have inverse negative slopes of each other. So if we compare the slopes of the two equations, then we can find the answer. For the first equation we have 
so the slope is
.
So for the equations to be perpendicular, the other equation needs to have a slope of 3. For the second equation, we have

so the slope is
.
Since the slope of the second equation is not equal to 3, then the lines are not perpendicular.
If two equations are perpendicular, then they will have inverse negative slopes of each other. So if we compare the slopes of the two equations, then we can find the answer. For the first equation we have
so the slope is .
So for the equations to be perpendicular, the other equation needs to have a slope of 3. For the second equation, we have
so the slope is .
Since the slope of the second equation is not equal to 3, then the lines are not perpendicular.
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Figure NOT drawn to scale.
Refer to the above figure.
True or false: 
Statement 1:
is a right angle.
Statement 2:
and
are supplementary.

Figure NOT drawn to scale.
Refer to the above figure.
True or false:
Statement 1: is a right angle.
Statement 2: and
are supplementary.
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Statement 1 alone establishes by definition that
, but does not establish any relationship between
and
.
By Statement 2 alone, since same-side interior angles are supplementary,
, but no conclusion can be drawn about the relationship of
, since the actual measures of the angles are not given.
Assume both statements are true. If two lines are parallel, then any line in their plane perpendicular to one must be perpendicular to the other.
and
, so it can be established that
.
Statement 1 alone establishes by definition that , but does not establish any relationship between
and
.
By Statement 2 alone, since same-side interior angles are supplementary, , but no conclusion can be drawn about the relationship of
, since the actual measures of the angles are not given.
Assume both statements are true. If two lines are parallel, then any line in their plane perpendicular to one must be perpendicular to the other. and
, so it can be established that
.
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Refer to the above figure.
. True or false: 
Statement 1: 
Statement 2:
and
are supplementary.

Refer to the above figure. . True or false:
Statement 1:
Statement 2: and
are supplementary.
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If transversal
crosses two parallel lines
and
, then same-side interior angles are supplementary, so
and
are supplementary angles. Also, corresponding angles are congruent, so
.
By Statement 1 alone, angles
and
are congruent as well as supplementary; by Statement 2 alone,
and
are also supplementary as well as congruent. Two angles that are both supplementary and congruent are both right angles, so from either statement alone,
and
intersect at right angles, so, consequently,
.
If transversal crosses two parallel lines
and
, then same-side interior angles are supplementary, so
and
are supplementary angles. Also, corresponding angles are congruent, so
.
By Statement 1 alone, angles and
are congruent as well as supplementary; by Statement 2 alone,
and
are also supplementary as well as congruent. Two angles that are both supplementary and congruent are both right angles, so from either statement alone,
and
intersect at right angles, so, consequently,
.
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Find the equation of the line that is perpendicular to the following equation and passes through the point
.

Find the equation of the line that is perpendicular to the following equation and passes through the point .
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To solve this equation, we want to begin by recalling how to find the slope of a perpendicular line. In this case, our original line is modeled by the following:

To find the slope of any line perpendicular to the above equation, we simply need to take the reciprocal of the first slope, and then change its sign. Our original slope is
, so

becomes
.
If we flip
, we get
, and the opposite sign of a negative is a positive; hence, our slope is positive
.
So, we know our perpendicular line should look something like this:

However, we need to find out what
(our
-intercept) is in order to complete our equation. To do so, we need to plug in the ordered pair we received in the question,
, and solve for
:




So, by putting everything together, we get our final equation:

This equation satisfies the conditions of being perpendicular to our initial equation and passing through
.
To solve this equation, we want to begin by recalling how to find the slope of a perpendicular line. In this case, our original line is modeled by the following:
To find the slope of any line perpendicular to the above equation, we simply need to take the reciprocal of the first slope, and then change its sign. Our original slope is , so
becomes
.
If we flip , we get
, and the opposite sign of a negative is a positive; hence, our slope is positive
.
So, we know our perpendicular line should look something like this:
However, we need to find out what (our
-intercept) is in order to complete our equation. To do so, we need to plug in the ordered pair we received in the question,
, and solve for
:
So, by putting everything together, we get our final equation:
This equation satisfies the conditions of being perpendicular to our initial equation and passing through .
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Two dice are rolled. What is the probability that the sum of both dice is greater than 8?
Two dice are rolled. What is the probability that the sum of both dice is greater than 8?
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There are 36 possible outcomes (
). 10 out of the 36 outcomes are greater than 8: (6 and 3)(6 and 4)(6 and 5)(6 and 6)(5 and 4)(5 and 5)(5 and 6)(4 and 5)(4 and 6)(3 and 6).

There are 36 possible outcomes (). 10 out of the 36 outcomes are greater than 8: (6 and 3)(6 and 4)(6 and 5)(6 and 6)(5 and 4)(5 and 5)(5 and 6)(4 and 5)(4 and 6)(3 and 6).
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What is the least common denominator of the following fractions?

What is the least common denominator of the following fractions?
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The least common denominator (LCD) is the lowest common multiple of the denominators.
Multiples of 5: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50
Multiples of 15: 15, 30, 45, 60, 75, 90,105,120, 135, 150
Multiples of 3: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30
The least common denominator is 15.
The least common denominator (LCD) is the lowest common multiple of the denominators.
Multiples of 5: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50
Multiples of 15: 15, 30, 45, 60, 75, 90,105,120, 135, 150
Multiples of 3: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30
The least common denominator is 15.
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Simplify the following into a single fraction.

Simplify the following into a single fraction.
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To simply, we must first find the common denominator of the two fractions. That would be
or 
Hence we multiply the first fraction by
and the second fraction by
, and we will have.
.
Now that the denominators match, we can add the fractions. The denominator stays the same after this, only the numerators add together.

Then factor out an
from the numerator to get the final answer.
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To simply, we must first find the common denominator of the two fractions. That would be or
Hence we multiply the first fraction by and the second fraction by
, and we will have.
.
Now that the denominators match, we can add the fractions. The denominator stays the same after this, only the numerators add together.
Then factor out an from the numerator to get the final answer.
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Rhombus
has diagonals
and
. What is the perimeter of the rhombus?

Rhombus has diagonals
and
. What is the perimeter of the rhombus?
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The rhombus is a special kind of a parallelogram. Its sides are all of the same length. Therefore, we just need to find one length of this quadrilateral. To do so, we can apply the Pythagorean Theorem on triangle AEC for example, since we know the length of the diagonals. Also, the diagonals intersect at their center. Therefore, triangle AEC has length,
and
. Therefore,
or
. The perimeter is then
.
The rhombus is a special kind of a parallelogram. Its sides are all of the same length. Therefore, we just need to find one length of this quadrilateral. To do so, we can apply the Pythagorean Theorem on triangle AEC for example, since we know the length of the diagonals. Also, the diagonals intersect at their center. Therefore, triangle AEC has length, and
. Therefore,
or
. The perimeter is then
.
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What is the sum of the prime numbers that are greater than 50 but less than 60?
What is the sum of the prime numbers that are greater than 50 but less than 60?
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A prime number is only divisible by the number 1 and itself. Of the integers between 50 and 60, all of the even integers are also divisible by the number 2 so they are not prime numbers. The integers 51 and 57 are divisible by 3. The integer 55 is divisible by 5. The only integers that are prime are 53 and 59. The sum of these two integers is 112.
A prime number is only divisible by the number 1 and itself. Of the integers between 50 and 60, all of the even integers are also divisible by the number 2 so they are not prime numbers. The integers 51 and 57 are divisible by 3. The integer 55 is divisible by 5. The only integers that are prime are 53 and 59. The sum of these two integers is 112.
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What is the product of the four smallest prime numbers?
What is the product of the four smallest prime numbers?
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We must remember that 0 and 1 are NOT prime numbers, but 2 is.
The four smallest prime numbers are 2, 3, 5, and 7. Then 2 * 3 * 5 * 7 = 210.
Note: There are NO negative prime numbers, so we don't have to look for tiny, negative numbers here.
We must remember that 0 and 1 are NOT prime numbers, but 2 is.
The four smallest prime numbers are 2, 3, 5, and 7. Then 2 * 3 * 5 * 7 = 210.
Note: There are NO negative prime numbers, so we don't have to look for tiny, negative numbers here.
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If a and b are even integers, what must be odd?
If a and b are even integers, what must be odd?
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The sum (or difference) or 2 even integers is even. Similarly, the product (or quotient) of 2 even integers is also even; therefore the answer must be
, which can be easily checked by plugging in any two even numbers.
For example, if
, which is odd.
The sum (or difference) or 2 even integers is even. Similarly, the product (or quotient) of 2 even integers is also even; therefore the answer must be , which can be easily checked by plugging in any two even numbers.
For example, if , which is odd.
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Three consecutive numbers add up to 36. What is the smallest number?
Three consecutive numbers add up to 36. What is the smallest number?
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The sum of 3 consecutive numbers would be

which simplifies into

Set that equation equal to 36 and solve.

The sum of 3 consecutive numbers would be
which simplifies into
Set that equation equal to 36 and solve.
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Becky has to choose from 4 pairs of pants, 6 shirts, and 2 pairs of shoes for an interview. If an outfit consists of 1 pair of pants, 1 pair of shoes, and 1 shirt, how many options does she have?
Becky has to choose from 4 pairs of pants, 6 shirts, and 2 pairs of shoes for an interview. If an outfit consists of 1 pair of pants, 1 pair of shoes, and 1 shirt, how many options does she have?
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To find total number, multiply the number of each item.

To find total number, multiply the number of each item.
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What is the greatest prime factor of 
What is the greatest prime factor of
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The only prime factors are 3 and 5, therefore, 5 will be the greatest prime factor.
The only prime factors are 3 and 5, therefore, 5 will be the greatest prime factor.
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Solve:

Solve:
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The sum is 8,053,467
The sum is 8,053,467
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For how many integers,
, is
an integer?
For how many integers, , is
an integer?
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Since the numerator is always 1 greater than the denominator, we know that for large enough values of
, it's never going to be an integer (one will be even, other odd). In fact, there are only 2 cases where this can be done. The first is dividing 0. Since 0 is divisible by every number, if the numerator is 0, then we will still get an integer. Thus one answer is 
The other answer occurs as a special case as well. We can divide any number by 1 evenly, so when the denominator is 1 we get an integer:

In every other case, we will have a non-integer.
Since the numerator is always 1 greater than the denominator, we know that for large enough values of , it's never going to be an integer (one will be even, other odd). In fact, there are only 2 cases where this can be done. The first is dividing 0. Since 0 is divisible by every number, if the numerator is 0, then we will still get an integer. Thus one answer is
The other answer occurs as a special case as well. We can divide any number by 1 evenly, so when the denominator is 1 we get an integer:
In every other case, we will have a non-integer.
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