All GMAT Math Resources
Example Questions
Example Question #32 : Powers & Roots Of Numbers
Which of the following is equal to the twelfth power of the cube root of ?
Assume to be positive.
The cube root of is raised to the power of one third, or . This raised to the power of twelve is
Example Question #32 : Powers & Roots Of Numbers
Which of the following expressions is equal to ?
Example Question #32 : Powers & Roots Of Numbers
Assume to be positive.
Multiply the eighth power of the fourth root of by the fourth power of the eighth root of . What is the product?
The fourth root of is ; the eighth power of this is .
The eighth root of is ; the fourth power of this is .
The product of these expressions is .
Example Question #31 : Understanding Powers And Roots
Which of the following is equal to the eighth root of the square of ?
Assume to be positive.
The fourth power of .
The fourth root of
The sixteenth power of .
The sixteenth root of .
The sixth root of
The fourth root of
The square of is . The eighth root of is raised to the power of , or
This is equivalent to , the fourth root of .
Example Question #33 : Powers & Roots Of Numbers
Which of the following numbers has a rational square root and a rational cube root?
Each of the choices is a power of 10, so rewrite each choice as such:
Since 10 itself does not have a rational square root, a necessary and sufficient condition for to have a rational square root - that is, for
to be rational - is for to be an integer. This allows us to eliminate and .
Similarly, for to have a rational cube root, must be an integer. This allows us to eliminate and .
is left. is the correct choice.
Example Question #34 : Powers & Roots Of Numbers
Assume to be negative.
Add the tenth power of the fifth root of to the fifth root of the tenth power of . What is the expression?
The tenth power of the fifth root of can be found as follows:
The fifth root of is ; the tenth power of this is .
The tenth power of is ; the fifth root of this is
The two expressions are equivalent, so they add up to .
Example Question #34 : Powers & Roots Of Numbers
Which of the following is equivalent to ?
This question requires that you understand negative exponents and fractional exponents. To make a negative exponent positive, simply switch its location in the fraction, so this:
becomes:
Then, we need to recognize how to rewrite fractional exponents. In a fractional exponent, the numerator stays as the power to which we are raising our base. The denominator becomes the index of our root. Thus, our fractional exponent becomes:
Four was the denominator of our fractional exponent, so it became the index of our root. In other words, something raised to the power of is the same thing as taking the fourth root of that something.
Example Question #61 : Arithmetic
How can be rewritten ?
To solve this problem, we must remember exponent rules. The powers here need to be added, since the powers are both raising to the same number. The final answer is or .
Example Question #41 : Understanding Powers And Roots
How can be rewritten?
Multiply the terms:
Alternatively, this problem can be solved by rewriting the fraction as a negative exponent:
Then, we can rewrite as . Using the rules of exponents, we multiply these exponents to get :
At this point, we can combine the two terms that have a base of :
Example Question #1621 : Gmat Quantitative Reasoning
Which of the following expressions is equal to ?
As soon as we see that this is a difference of exponential factors that have a common base of 5, we should ask ourselves whether we can factor any common factors out of the terms. We can rewrite the expression using the rules of exponents to reveal a common factor of :
At this point, we can factor out :
is one of the listed answers, so we have arrived at the correct answer.