Call Now to Set Up Tutoring:

(888) 888-0446

PSAT Math : How to find inverse variation

Study concepts, example questions & explanations for PSAT Math

Create An Account

All PSAT Math Resources

10 Diagnostic Tests 421 Practice Tests Question of the Day Flashcards Learn by Concept

Example Questions

← Previous 1 2 Next →

Example Question #41 : Algebraic Fractions

A school's tornado shelter has enough food to last 20 children for 6 days. If 24 children ended up taking shelter together, for how many fewer days will the food last?

Possible Answers:

Correct answer:

Explanation:

Because the number of days goes down as the number of children goes up, this problem type is inverse variation. We can solve this problem by the following steps:

20*6=24*x

120=24x

x=120/24

x=5

In this equation, x represents the total number of days that can be weathered by 24 students. This is down from the 6 days that 20 students could take shelter together. So the difference is 1 day less.

Report an Error

Example Question #1 : How To Find Inverse Variation

varies inversely as the cube of .

If A = 8 when B = 66 , then evaluate when B = 100 . (Nearest tenth)

Possible Answers:

7.0

27.8

9.2

2.3

5.3

Correct answer:

2.3

Explanation:

If varies inversely as the cube of , then, if A ,B are the initial values of the variables and A' ,B' are the final values,

$A'B' ^{3} = AB^{3}$

Substitute A = 8, B = 66, B'= 100 and find :

$A' \cdot 100 ^{3} = 8 \cdot 66^{3}$

$A' =\frac{ 8 \cdot 66^{3}}{100^{3}} = \frac{ 8 \cdot 287,496}{1,000,000} =2.299968$

This rounds to 2.3.

Report an Error

Example Question #1 : How To Find Inverse Variation

varies inversely as the cube root of .

If A = 8 when B = 66 , then evaluate when B = 100 . (Nearest tenth)

Possible Answers:

2.3

27.8

7.0

5.3

9.2

Correct answer:

7.0

Explanation:

If varies inversely as the cube root of , then, if A ,B are the initial values of the variables and A' ,B' are the final values,

$A'\sqrt[3]{B'} = A\sqrt[3]{B}$

Substitute A = 8, B = 66, B'= 100 and find :

$A'\sqrt[3]{100} = 8\sqrt[3]{66}$

$A'=\frac{ 8\sqrt[3]{66}}{\sqrt[3]{100} } \approx \frac{ 8 \cdot 4.0412}{4.6416} \approx 7.0$

Report an Error

Example Question #1 : How To Find Inverse Variation

Find the inverse of

$y=\frac{1}{2}x-4$

Possible Answers:

y=2x+8

y=x-4

y=2x-8

y=2x+4

Correct answer:

y=2x+8

Explanation:

To find the inverse we first switch the x and y variables

$x=\frac{1}{2}y-4$

Now we add 4 to each side

$x+4=\frac{1}{2}y$

From here to isolate y we need to multiply each side by 2

2(x+4)=y

By distributing the 2 we get our final solution:

y=2x+8

Report an Error

Example Question #4 : How To Find Inverse Variation

varies inversely as the square of .

If A = 8 when B = 66 , then evaluate when B = 100 . (Nearest tenth)

Possible Answers:

5.3

9.8

3.5

6.5

18.4

Correct answer:

3.5

Explanation:

If varies inversely as the square of , then, if A ,B are the initial values of the variables and A' ,B' are the final values,

$A'B' ^{2} = AB^{2}$ .

Substitute A = 8, B = 66, B'= 100 and find :

$A' \cdot 100 ^{2} = 8 \cdot 66^{2}$

$A' =\frac{ 8 \cdot 66^{2}}{100^{2}} =\frac{ 8 \cdot 66^{2}}{100^{2}} = \frac{ 8 \cdot 4,356}{10,000} =3.4848$

This rounds to 3.5.

Report an Error

Example Question #1 : How To Find Inverse Variation

varies inversely with the square root of .

If A = 8 when B = 66 , then evaluate when B = 100 . (Nearest tenth)

Possible Answers:

18.4

6.5

5.3

3.5

9.8

Correct answer:

6.5

Explanation:

If varies inversely with the square root of , then, if A ,B are the initial values of the variables and A' ,B' are the final values,

$A'\sqrt{B'} = A\sqrt{B}$ .

Substitute A = 8, B = 66, B'= 100 and find :

$A'\sqrt{100} = 8\sqrt{66}$

$A'=\frac{ 8\sqrt{66}}{\sqrt{100} } \approx \frac{ 8 \cdot 8.1240}{10} \approx 6.5$

Report an Error

Example Question #1 : How To Find Inverse Variation

Find the inverse of y=2x+1 .

Possible Answers:

$y=\frac{x-1}{2}$

y=x+2

y=2x-1

y=x-1

Correct answer:

$y=\frac{x-1}{2}$

Explanation:

To find the inverse of a function we need to first switch the and . Therefore, y=2x+1 becomes

x=2y+1

We now solve for y by subtracting 1 from each side

x-1=2y

From here we divide both sides by 2 which results in

$y=\frac{x-1}{2}$

Report an Error

Example Question #7 : How To Find Inverse Variation

Find the inverse of 9y=3x+12 .

Possible Answers:

y=3x+4

y=9x+12

y=3x-4

y=4x-3

Correct answer:

y=3x-4

Explanation:

To find the inverse we first switch the variables then solve for y.

9x=3y+12

Then we subtract from each side

9x-12=3y

Now we divide by to get our final answer. When we divide by we are left with . When we divide by we are left with . Thus resulting in:

y=3x-4

Report an Error

Example Question #1 : How To Find Inverse Variation

Find the inverse equation of:

3y-2x=20

Possible Answers:

$\frac{2x-20}{3}=y$

$\frac{1}{2}x+10=y$

$\frac{2x+20}{3}=y$

$\frac{3x-20}{2}=y$

Correct answer:

$\frac{3x-20}{2}=y$

Explanation:

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

$\frac{3x-20}{2}=y$

Report an Error

Example Question #1 : How To Find Inverse Variation

Find the inverse equation of 5x-4y=18 .

Possible Answers:

$x=\frac{4y+18}{5}$

$y=\frac{4x+18}{5}$

$y=\frac{4x+5}{18}$

x=y

$y=\frac{x+18}{4}$

Correct answer:

$y=\frac{4x+18}{5}$

Explanation:

5x-4y=18

1. Switch the and variables in the above equation.

5y-4x=18

2. Solve for :

5y-4x=18

5y-4x+4x=18+4x

5y=4x+18

$\frac{5y}{5}=\frac{4x+18}{5}$

$y=\frac{4x+18}{5}$

Report an Error

← Previous 1 2 Next →

View PSAT Mathematics Tutors

Eva
Certified Tutor

Technicka Univerzita Liberec, Bachelor of Education, Education.

View PSAT Mathematics Tutors

Shakeel
Certified Tutor

View PSAT Mathematics Tutors

Joseph
Certified Tutor

CUNY College of Staten Island, Bachelor in Arts, Applied Psychology. New York University, Master of Arts, Applied Psychology.

All PSAT Math Resources

10 Diagnostic Tests 421 Practice Tests Question of the Day Flashcards Learn by Concept

Popular Subjects

Algebra Tutors in Denver, ISEE Tutors in Boston, Math Tutors in Houston, ISEE Tutors in Phoenix, GRE Tutors in Seattle, Computer Science Tutors in Dallas Fort Worth, Calculus Tutors in Boston, Calculus Tutors in Los Angeles, ACT Tutors in Atlanta, Physics Tutors in Chicago

Popular Courses & Classes

ISEE Courses & Classes in Houston, ISEE Courses & Classes in Seattle, MCAT Courses & Classes in Chicago, GMAT Courses & Classes in Chicago, MCAT Courses & Classes in Denver, SAT Courses & Classes in Chicago, GRE Courses & Classes in New York City, GMAT Courses & Classes in Washington DC, ACT Courses & Classes in San Diego, SAT Courses & Classes in Philadelphia

Popular Test Prep

ISEE Test Prep in Houston, MCAT Test Prep in Washington DC, MCAT Test Prep in New York City, ACT Test Prep in Dallas Fort Worth, SSAT Test Prep in Seattle, GMAT Test Prep in Chicago, LSAT Test Prep in Phoenix, MCAT Test Prep in San Diego, SSAT Test Prep in Washington DC, GMAT Test Prep in Philadelphia

DMCA Complaint

If you believe that content available by means of the Website (as defined in our Terms of Service) infringes one or more of your copyrights, please notify us by providing a written notice (“Infringement Notice”) containing the information described below to the designated agent listed below. If Varsity Tutors takes action in response to an Infringement Notice, it will make a good faith attempt to contact the party that made such content available by means of the most recent email address, if any, provided by such party to Varsity Tutors.

Your Infringement Notice may be forwarded to the party that made the content available or to third parties such as ChillingEffects.org.

Please be advised that you will be liable for damages (including costs and attorneys’ fees) if you materially misrepresent that a product or activity is infringing your copyrights. Thus, if you are not sure content located on or linked-to by the Website infringes your copyright, you should consider first contacting an attorney.

Please follow these steps to file a notice:

You must include the following:

A physical or electronic signature of the copyright owner or a person authorized to act on their behalf; An identification of the copyright claimed to have been infringed; A description of the nature and exact location of the content that you claim to infringe your copyright, in \ sufficient detail to permit Varsity Tutors to find and positively identify that content; for example we require a link to the specific question (not just the name of the question) that contains the content and a description of which specific portion of the question – an image, a link, the text, etc – your complaint refers to; Your name, address, telephone number and email address; and A statement by you: (a) that you believe in good faith that the use of the content that you claim to infringe your copyright is not authorized by law, or by the copyright owner or such owner’s agent; (b) that all of the information contained in your Infringement Notice is accurate, and (c) under penalty of perjury, that you are either the copyright owner or a person authorized to act on their behalf.

Send your complaint to our designated agent at:

Charles Cohn Varsity Tutors LLC
101 S. Hanley Rd, Suite 300
St. Louis, MO 63105

Or fill out the form below:

Do not fill in this field

Contact Information

* Full legal name

Company name

* Phone number

* Email address

Address

* Address1

Address2

* City

* State

* Zipcode

* Country

Complaint Details

* URL of copyrighted work (where your original material is located)

* Please describe the copyrighted work so that it may be easily identified

I am the owner, or an agent authorized to act on behalf of the owner of an exclusive right that is allegedly infringed.

I have a good faith belief that the use of the material in the manner complained of is not authorized by the copyright owner, its agent, or the law.

This notification is accurate.

I acknowledge that there may be adverse legal consequences for making false or bad faith allegations of copyright infringement by using this process.

* Signature (your digital signature is legally binding)

HIGH SCHOOL

GRADUATE SCHOOL

K-8

Search 50+ Tests

math tutoring

science tutoring

foreign languages

elementary tutoring

other

Search 350+ Subjects

PSAT Math : How to find inverse variation

Study concepts, example questions & explanations for PSAT Math

All PSAT Math Resources

Example Questions

Example Question #41 : Algebraic Fractions

Example Question #1 : How To Find Inverse Variation

Example Question #1 : How To Find Inverse Variation

Example Question #1 : How To Find Inverse Variation

Example Question #4 : How To Find Inverse Variation

Example Question #1 : How To Find Inverse Variation

Example Question #1 : How To Find Inverse Variation

Example Question #7 : How To Find Inverse Variation

Example Question #1 : How To Find Inverse Variation

Example Question #1 : How To Find Inverse Variation

All PSAT Math Resources

Report an issue with this question

DMCA Complaint

Contact Information

Address

Complaint Details

Email address:
Your name:
Feedback: