All GRE Math Resources
Example Questions
Example Question #91 : How To Find The Solution To An Equation
Pets Plus makes bird houses. Their monthly fixed expenses are $750. The cost for each bird house is $15. The bird houses sell for $40.
If Pets Plus sells 50 bird houses, what is the profit?
Let = the number of birdhouses sold each month.
Substituting in 50 for gives an answer of 500, so the profit on 50 birdhouses is $500.
Example Question #52 : Algebra
George is three times older than Joey. The sum of their ages is 16. What is the product of their ages?
Let = Joey's age and = George's age.
Then the equation to solve becomes .
Therefore, Joey is 4 years old and George is 12 years old, so the product of their ages is 48.
Example Question #53 : Algebra
Three consecutive even numbers add to 42. What is the middle number?
Let = 1st even number, = 2nd even number, and = 3rd even number.
Then the equation to solve becomes .
Thus , so the middle number is 14.
Example Question #51 : Equations / Inequalities
Consider the following equation:
Which of the following must be true?
The quantity inside the absolute value brackets must equal either or , depending on whether the quantity inside the brackets is positive or negative. We therefore have two seperate equations:
To solve the first equation, add 9 to both sides:
Subtract from both sides:
This is the first solution. Now let's look at the second equation. The distributive law gives us:
Add 9 to both sides:
Add to both sides:
Divide both sides by 3:
Therefore, is either 4 or 6.
Statement does NOT have to be true because can also equal 4.
Statement must be true because both 4 and 6 are positive .
Finally, statement always holds because 4 and 6 are both even.
Example Question #51 : Algebra
If
,
then
Divide both sides by 300 to get . Subtract 7 and divide by two to get .
Example Question #151 : Gre Quantitative Reasoning
If b – 3 = a, then (a – b)2 =
–9
–3
3
The answer cannot be determined from the given information.
9
9
The quantity can be regrouped to be –3 = a – b. Thus, (a – b)2 = (–3)2 = 9.