All GRE Math Resources
Example Questions
Example Question #3 : How To Find The Lowest / Least Common Denominator
In simplest form,
First, find the smallest number that both and will factor into, which is .
This means that the fist fraction should be multiplied by and the second should be multiplied by .
Therefore,
.
Then, add the numerators while the denomenators stay the same:
.
Then, reduce the fraction to its lowest terms:
.
Example Question #61 : Fractions
For how many integers, , between 26 and 36 is it true that
and are all in lowest terms?
If is even, then is not in lowest terms, since both and 4 are divisible by 2. Therefore, the only possibilities are 27,29,31,33, and 35. But , , and , so only two integers satisfy the given condition: 29 and 31.
Example Question #61 : Fractions
Mrs. Lawrence's class has students, of which are girls. If you were to choose a student at random, what's the probability that the student chosen would be a boy?
In order to find out the probability of choosing a boy, you must first find out how many boys there are. Since there are girls out of students, students should be boys.
Therefore, the probability of choosing a boy is,
.
However, this is not one of the answer choices; therefore, you must reduce the fraction.
In order to reduce a fraction, you have to find their GCM, or greatest common multiple. This is the biggest number that will go into both the numerator and denominator . The largest number is . Divide both the top and bottom by , and you will get the answer:
Example Question #3 : Simplifying Fractions
Simplify the fraction:
To simplify the fraction
It may be helpful to write it in terms of scientific notation:
Example Question #1063 : Gre Quantitative Reasoning
Simply the fraction:
To simplify the fraction
Begin by factoring out common terms in the numerator and denominator:
Now notice that the coefficients for the polynomials in the numerator and denominator match the form of Pascal's Triangle:
The fraction can be rewritten as:
And finally reduced to
Example Question #1061 : Gre Quantitative Reasoning
and are positive integers.
is a multiple of .
Quantity A:
Quantity B:
The relationship cannot be determined.
Quantity A is greater.
The two quantities are equal.
Quantity B is greater.
The relationship cannot be determined.
Recall that the exponent of the denominator is sutracted from the exponent of the numerator.
Therefore Quantity A is equivalent to x5–y, and because we would then be comparing an arithmetic operation to a geometric operation, it does not matter whether y is a multiple of 5. The two quantities cannot be compared.
Example Question #13 : Mixed / Improper Fractions
Which of the following is the mixed fraction equivalent to ?
To begin, notice that using your calculator, you can find:
Now, the closest even multiple of that is less than is . Therefore, you know that your number is:
This is the same as:
, or simply, . This is your mixed fraction.
Example Question #63 : Fractions
Which of the following is equivalent to ?
Although there are many ways to convert improper fractions into mixed fractions, the easiest way is to use your calculator to your advantage. Begin by dividing by . This gives you . Therefore, you can eliminate all the options that have do not have for their first portion. Next, multiply by the denominator (), and get . This means that you have and , or . Thus, your answer is .
Example Question #2 : Mixed / Improper Fractions
Quantity A:
Quantity B:
Which of the following is true?
The two quantities are equal
Quantity A is larger.
Quantity B is larger.
The relationship of the two quantities cannot be determined based on the information provided.
The two quantities are equal
Though there are several ways you could solve this, let's convert the improper fraction into a mixed one so we can compare them. Start by dividing by . This gives you
Now, since we know that the two numbers have the same whole-number value, we need to compare their decimal portions. Compare to . The latter is indeed Therefore, the two values are equal.
Example Question #455 : Arithmetic
Write as an improper fraction.
To find the improper fraction value, we must effectively add together 71 and 5/7. To do this, we will give 71 a denominator of 7; therefore, we are transforming 71/1 to x/7. The shortest way to do this is to multiply by 7/7 (which really is 1); therefore, 71 = 71 * (7/7) = 497/7.
Now add them: (497 + 5)/7 = 502/7