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 #62 : 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 #62 : Fractions
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 #1 : How To Find Out A Mixed Fraction From An Improper Fraction
and are positive integers.
is a multiple of .
Quantity A:
Quantity B:
The two quantities are equal.
The relationship cannot be determined.
Quantity A is greater.
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 #1473 : Sat Mathematics
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 #1 : Mixed / Improper 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 : How To Find Out A Mixed Fraction From An Improper Fraction
Quantity A:
Quantity B:
Which of the following is true?
Quantity A is larger.
The two quantities are equal
The relationship of the two quantities cannot be determined based on the information provided.
Quantity B is larger.
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 #1 : Mixed / Improper Fractions
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