All GRE Math Resources
Example Questions
Example Question #1 : Operations
Solve for :
Begin by isolating the factors:
Now, the common denominator of these two fractions is . Therefore, multiply by :
Now, you can subtract the left values:
Now, multiply both sides by :
Example Question #2 : Operations
Simplify:
Just like adding fractions, when you subtract fractions, you need to find a common denominator. For and , the least common denominator is . In order to do your subtraction, you need to multiply appropriately to give your fractions this denominator:
Which is the same as...
Now, you can subtract the numerators and retain the denominator:
Example Question #2 : Operations
Which of the following is true?
Quantity A:
Quantity B:
Quantity B is larger.
Quantity A is larger.
The two quantities are equal.
The relationship between the quantities cannot be determined.
Quantity A is larger.
First, consider each quantity separately.
Quantity A
These two fractions do not have a common factor. Their common denominator is . Thus, we multiply the fractions as follows to give them a common denominator:
This is the same as:
Quantity B
The common denominator of these two values is . Therefore, you multiply the fractions as follows to give them a common denominator:
This is the same as:
Since Quantity A is larger than and Quantity B is a positive fraction less than , we know that Quantity A is larger without even using a calculator.