GRE Math : GRE Quantitative Reasoning

Study concepts, example questions & explanations for GRE Math

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

Example Questions

Example Question #2 : How To Find Excluded Values

Find the excluded values of the following algebraic fraction

Possible Answers:

The numerator cancels all the binomials in the denomniator so ther are no excluded values.

Correct answer:

Explanation:

To find the excluded values of a algebraic fraction you need to find when the denominator is zero. To find when the denominator is zero you need to factor it. This denominator factors into 

so this is zero when x=4,7 so our answer is 

Example Question #1 : How To Find Inverse Variation

Find the inverse equation of:

 

Possible Answers:

Correct answer:

Explanation:

To solve for an inverse, we switch x and y and solve for y. Doing so yields:

 

 

Example Question #1 : How To Find Inverse Variation

Find the inverse equation of  .

Possible Answers:

Correct answer:

Explanation:

1. Switch the  and  variables in the above equation.

 

2. Solve for :

 

Example Question #2 : How To Find Inverse Variation

When ,  .

When .

If  varies inversely with , what is the value of  when ?

Possible Answers:

Correct answer:

Explanation:

If  varies inversely with .

 

1. Using any of the two  combinations given, solve for :

Using :

 

2. Use your new equation  and solve when :

 

Example Question #3 : How To Find Inverse Variation

x

y

If  varies inversely with , what is the value of ?

Possible Answers:

Correct answer:

Explanation:

An inverse variation is a function in the form:  or , where  is not equal to 0. 

Substitute each  in .

Therefore, the constant of variation, , must equal 24. If  varies inversely as must equal 24. Solve for .

Example Question #1 : How To Find Inverse Variation

 and  vary inversely. When . When . What does  equal when ?

Possible Answers:

Correct answer:

Explanation:

Because we know  and  vary inversely, we know that  for some .

When .

When .

Therefore, when , we have  so 

Example Question #1 : How To Evaluate A Fraction

Evaluate the following equation when  and round your answer to the nearest hundredth.

Possible Answers:

Correct answer:

Explanation:

 

1. Plug in  wherever there is an  in the above equation.

2. Perform the above operations.

Example Question #2 : How To Evaluate A Fraction

Mary walked to school at an average speed of 2 miles per hour and jogged back along the same route at an average speed of 6 miles per hour. If her total traveling time was 1 hour, what was the total number of miles in the round trip?

Possible Answers:

Correct answer:

Explanation:

Since Mary traveled 3 times as quickly coming from school as she did going to school (6 miles per hour compared to 2 miles per hour), we know that Mary spent only a third of the time coming from school as she did going. If x represents the number of hours it took to get to school, then x/3 represents the number of hours it took her to return.

Knowing that the total trip took 1 hour, we have:

x/3 = 1

3x/3 + 1x/3 = 1

4x/3 = 1

 = 3/4

So we know it took Mary 3/4 of an hour to travel to school (and the remaining 1/4 of an hour to get back).

Remembering that distance =  rate * time, the distance Mary traveled on her way to school was (2 miles per hour) * (3/4 of an hour) = 3/2 miles. Furthermore, since she took the same route coming back, she must have traveled 3/2 of a mile to return as well.

Therefore, the the total number of miles in Mary's round trip is 3/2 miles + 3/2 miles = 6/2 miles = 3 miles.

Example Question #3 : How To Evaluate A Fraction

If w=\frac{1}{8} then which of the following is equal to ?

Possible Answers:

\frac{1}{16}

\frac{1}{64}

\frac{1}{4}

\frac{1}{2}

\frac{1}{32}

Correct answer:

\frac{1}{4}

Explanation:

To raise \frac{1}{8} to the exponent \frac{2}{3}, square \frac{1}{8} and then take the cube root.

Example Question #12 : Algebraic Fractions

Solve   Actmath_7_113_q10_1

 

Possible Answers:

no solution

–1

infinitely many solutions

0

Correct answer:

infinitely many solutions

Explanation:

The common denominator of the left side is x(x–1). Multiplying the top and bottom of 1/x by (x–1) yields

Actmath_7_113_q10_2

Actmath_7_113_q10_3

Actmath_7_113_q10_4

Actmath_7_113_q10_5

 

Since this statement is true, there are infinitely many solutions. 

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