Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized for You

we will pick new questions that match your level based on your Timer History

Track Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

It appears that you are browsing the GMAT Club forum unregistered!

Signing up is free, quick, and confidential.
Join other 500,000 members and get the full benefits of GMAT Club

Registration gives you:

Tests

Take 11 tests and quizzes from GMAT Club and leading GMAT prep companies such as Manhattan GMAT,
Knewton, and others. All are free for GMAT Club members.

Applicant Stats

View detailed applicant stats such as GPA, GMAT score, work experience, location, application
status, and more

Books/Downloads

Download thousands of study notes,
question collections, GMAT Club’s
Grammar and Math books.
All are free!

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

This topic is locked. If you want to discuss this question please re-post it in the respective forum.

Here is a question which can become trickier depending upon your interpretation:

At Larry's Auto Supply Store, Brand X antifreeze is sold by the gallon and Brand Y motor oil is sold by the quart. Excluding sales tax, what is the total cost for 1 gallon of Brand X antifreeze and 1 quart of Brand Y motor oil?

(1). Excluding sales tax, the total cost for 6 gallons of Brand X antifreeze and 10 quarts of Brand Y motor oil is 58. (There is no quantity discount.)

(2). Excluding sales tax, the total cost for 4 gallons of Brand X antifreeze and 12 quarts of Brand Y motor oil is 44. (There is no quantity discount.)

Each statement on it's own leaves itself open to an almost infinite number of possible prices for X and Y. Only by combining them do we get our 2 equations for 2 variables. Normally you would want to answer C and move on, but we can do the math here to show it.

6x+10y=58
4x+12y=44

combine them:

2x-2y=14
2x=2y+14
x=y+7

plug it back in

6(y+7)+10y=58
6y+42+10y=58
16y=16
y=1

plug that back in

4x+12(1)=44
4x=32
x=8

so now plug 1 and 8 in to make sure they work

6(8)+10(1)=58
48+10=58
58=58 checks out

4(8)+12(1)=44
32+12=44
44=44 checks out

and there's your answer. 1 gallon of X and 1 quart of Y = $9

you don't need to convert quarts to gallons for this question, because the base/unit prices of the liquids are not the same. Just think of buying tables and chairs, you don't pay for them per volume of wood.