GRE Math : How to find absolute value

Study concepts, example questions & explanations for GRE Math

varsity tutors app store varsity tutors android store varsity tutors ibooks store

Example Questions

Example Question #1 : Absolute Value

Quantitative Comparison:

 

Column A

|–3 + 4|

 

Column B

|–3| + |4|

Possible Answers:

Column A is greater

Column B is greater

Column A and B are equal

Cannot be determined

Correct answer:

Column B is greater

Explanation:

The operations in the absolute value are always done first. So in Column A, |–3 + 4| = |1| = 1.  In Column B, |–3| + |4| = 3 + 4 = 7.

Example Question #2 : Absolute Value

Quantitative Comparison

|x – 3| = 3

Quantity A: x

Quantity B: 2

Possible Answers:

Quantity B is greater.

The relationship cannot be determined from the information given.

Quantity A is greater.

The two quantities are equal.

Correct answer:

The relationship cannot be determined from the information given.

Explanation:

It's important to remember that absolute value functions yield two equations, not just one. Here we have x – 3 = 3 AND x – 3 = –3.  

Therefore x = 6 or x = 0, so the answer cannot be determined.  

If we had just used the quation x – 3 = 3 and forgotten about the second equation, we would have had x = 6 as the only solution, giving us the wrong answer.

Example Question #3 : Absolute Value

Quantitative Comparison

Quantity A: |10| – |16|

Quantity B: |1 – 5| – |3 – 6|

Possible Answers:

The relationship cannot be determined from the information given.

Quantity A is greater.

Quantity B is greater.

The two quantities are equal.

Correct answer:

Quantity B is greater.

Explanation:

Quantity A: |10| = 10, |16| = 16, so |10| – |16| = 10 – 16 = –6.

Quantity B: |1 – 5| = 4, |3 – 6| = 3, so |1 – 5| - |3 – 6| = 4 – 3 = 1.

1 is bigger than –6, so Quantity B is greater.

Example Question #4 : Absolute Value

Quantitative Comparison

Quantity A: (|–4 + 1| + |–10|)2

Quantity B: |(–4 + 1 – 10)2|

Possible Answers:

The relationship cannot be determined from the information given.

Quantity A is greater.

The two quantities are equal.

Quantity B is greater.

Correct answer:

The two quantities are equal.

Explanation:

Quantity A: |–4 + 1| = |–3| = 3 and |–10| = 10, so (|–4 + 1| + |–10|)2 = (3 + 10)2 = 13= 169

Quantity B: |(–4 + 1 – 10)2| = |(–13)2| = 169

The two quantities are equal.

Example Question #5 : Absolute Value

Quantity A:

Quantity B:

Possible Answers:

Quantity A is greater

The two quantities are equal

The relationship cannot be determined from the information given

Quantity B is greater

Correct answer:

Quantity B is greater

Explanation:

If , then either  or  must be negative, but not both. Making them both positive, as in quantity B, and then adding them, would produce a larger number than adding them first and making the result positive.

Example Question #6 : Absolute Value

What is the absolute value of the following equation when

 

Possible Answers:

Correct answer:

Explanation:

(–3)3 = –27. Any time a negative number is cubed, it remains negative. –27 + 5 = –22. The absolute value of any number will ALWAYS be positive so the absolute value of –22 is 22. This is our answer.

 

Tired of practice problems?

Try live online GRE prep today.

1-on-1 Tutoring
Live Online Class
1-on-1 + Class
Learning Tools by Varsity Tutors