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:

A closed aluminum rectangular box has inner dimensions x centimeters [#permalink]

Show Tags

21 Oct 2012, 11:07

2

This post received KUDOS

11

This post was BOOKMARKED

00:00

A

B

C

D

E

Difficulty:

75% (hard)

Question Stats:

60% (02:41) correct
40% (02:31) wrong based on 233 sessions

HideShow timer Statistics

A closed aluminum rectangular box has inner dimensions x centimeters by y centimeters by z centimeters. Each of the six sides of the box is 1 centimeter thick. Calculate the volume of the aluminium, in cubic centimeters?

Are we really concerned with the extra 1cm thickness in calculating the volume? The thickness does not add to spaces to be filled; so, how come it is affecting the volume?

Re: A closed aluminum rectangular box has inner dimensions x centimeters [#permalink]

Show Tags

21 Oct 2012, 11:27

gmatbull wrote:

A closed aluminum rectangular box has inner dimensions x centimeters by y centimeters by z centimeters. Each of the six sides of the box is 1 centimeter thick. Calculate the volume of the plastic, in cubic centimeters?

A. xyz + 8 B. 2(xy + xz + yz + 4) C. 2(xy + xz + yz) – xyz D. 2(xy + xz + yz + x + y + z + 4) E. 2(xy + xz + yz + 2x + 2y + 2z + 4)

Are we really concerned with the extra 1cm thickness in calculating the volume? The thickness does not add to spaces to be filled; so, how come it is affecting the volume?

What does plastic do? questions looks incomplete.

The most logical meaning we can draw out of it is that you are going to cover the alumunium box with the plastic. In such case you need to add +1 cm because inner dimensions are given and cover would be calculated based on outer dimensions. Second case, if you are going to fill in the plastic - in that case you dont need to care about +1 cm. and inner volume should suffice. Hope it helps.
_________________

A closed aluminum rectangular box has inner dimensions x centimeters by y centimeters by z centimeters. Each of the six sides of the box is 1 centimeter thick. Calculate the volume of the aluminium, in cubic centimeters?

A. xyz + 8 B. 2(xy + xz + yz + 4) C. 2(xy + xz + yz) – xyz D. 2(xy + xz + yz + x + y + z + 4) E. 2(xy + xz + yz + 2x + 2y + 2z + 4)

Are we really concerned with the extra 1cm thickness in calculating the volume? The thickness does not add to spaces to be filled; so, how come it is affecting the volume?

Inner volume of the box is \(xyz\) cubic centimeters.

Now, since each of the six sides of the box is 1 centimeter thick, then outer dimensions are \(x+2\) by \(y+2\) by \(z+2\) centimeters. Therefore, the volume of the box with aluminium is \((x+2)(y+2)(z+2)\) cubic centimeters.

The volume of the aluminium is the difference of these two: \((x+2)(y+2)(z+2)-xyz=2(xy + xz + yz + 2x + 2y + 2z + 4)\).

Answer: E.

OR:

Plug numbers: say \(x=y=z=1\), then the inner volume is 1 cubic centimeters and the volume of the whole box is \((1+2)(1+2)(1+2)=27\) cubic centimeters. The volume of the aluminium is 27-1=26 cubic centimeters.

Now, plug \(x=y=z=1\) and see which options yields 26: only answer choice E fits.

Answer: E.

P.S. For plug-in method it might happen that for some particular numbers more than one option may give "correct" answer. In this case just pick some other numbers and check again these "correct" options only.
_________________

The question itself is very clear and not hard but it took me ages to multiple three brackets without a mistake. Is there a trick? Thanks
_________________

The question itself is very clear and not hard but it took me ages to multiple three brackets without a mistake. Is there a trick? Thanks

You have to put pen to paper as verbal calculation of the bracket will make issues complicated. Try solving first two brackets first and then multiply with the third one. Also, to avoid careless mistakes, always follow a pattern so that you don't miss anything. for eg ( a + b) ( c + d) = a( c + d) + b ( c + d) always multiply with a pattern . Hope this helps.
_________________

Fire the final bullet only when you are constantly hitting the Bull's eye, till then KEEP PRACTICING.

A WAY TO INCREASE FROM QUANT 35-40 TO 47 : http://gmatclub.com/forum/a-way-to-increase-from-q35-40-to-q-138750.html

Q 47/48 To Q 50 + http://gmatclub.com/forum/the-final-climb-quest-for-q-50-from-q47-129441.html#p1064367

Three good RC strategies http://gmatclub.com/forum/three-different-strategies-for-attacking-rc-127287.html

The question itself is very clear and not hard but it took me ages to multiple three brackets without a mistake. Is there a trick? Thanks

Start with multiplying the first two in the product of the three factors:

\((x+2)(y+2)(z+2)=(xy+2x+2y+4)(z+2)\)

No need to fully carry out the other multiplication. You can see that there will be one term of \(xyz\), which will cancel out in the final expression with \(-xyz\). In addition, you will have terms containing products of two factors - like \(xy, \,\,xz\), and \(yz\). All will have a coefficient of 2 in front. Then the terms with \(x, \,\,y,\) and \(z\), all have a coefficient of 4 in front. Answers A, B, and C can be eliminated. Between D and E, obviously E wins.
_________________

PhD in Applied Mathematics Love GMAT Quant questions and running.

Re: A closed aluminum rectangular box has inner dimensions x centimeters [#permalink]

Show Tags

11 Dec 2013, 13:48

A closed aluminum rectangular box has inner dimensions x centimeters by y centimeters by z centimeters. Each of the six sides of the box is 1 centimeter thick. Calculate the volume of the aluminium, in cubic centimeters?

A. xyz + 8 B. 2(xy + xz + yz + 4) C. 2(xy + xz + yz) – xyz D. 2(xy + xz + yz + x + y + z + 4) E. 2(xy + xz + yz + 2x + 2y + 2z + 4)

We are trying to find the volume of the aluminum, NOT the empty space inside the box.

In the INNER dimensions are x*y*z then the dimensions of the box including the one inch thick sides are going to be two CM greater as shown in the attached diagram (in a way, this is similar to a "walkway surrounding a rectangular garden" problem, except in 3 dimensions) Therefore, the length of the box (not just the interior dimensions) is (L+2) The width is (W+2) and the height is (H+2) --> (L+2)*(W+2)*(H+2) is the volume of the box if we consider the volume of the sides included. If we are to figure out the volume of JUST the sides we subtract from (L+2)*(W+2)*(H+2) the volume of the empty space (L*W*H)

Re: A closed aluminum rectangular box has inner dimensions x centimeters [#permalink]

Show Tags

02 Sep 2017, 09:51

Bunuel wrote:

gmatbull wrote:

A closed aluminum rectangular box has inner dimensions x centimeters by y centimeters by z centimeters. Each of the six sides of the box is 1 centimeter thick. Calculate the volume of the aluminium, in cubic centimeters?

A. xyz + 8 B. 2(xy + xz + yz + 4) C. 2(xy + xz + yz) – xyz D. 2(xy + xz + yz + x + y + z + 4) E. 2(xy + xz + yz + 2x + 2y + 2z + 4)

Are we really concerned with the extra 1cm thickness in calculating the volume? The thickness does not add to spaces to be filled; so, how come it is affecting the volume?

Inner volume of the box is \(xyz\) cubic centimeters.

Now, since each of the six sides of the box is 1 centimeter thick, then outer dimensions are \(x+2\) by \(y+2\) by \(z+2\) centimeters. Therefore, the volume of the box with aluminium is \((x+2)(y+2)(z+2)\) cubic centimeters.

The volume of the aluminium is the difference of these two: \((x+2)(y+2)(z+2)-xyz=2(xy + xz + yz + 2x + 2y + 2z + 4)\).

Answer: E.

OR:

Plug numbers: say \(x=y=z=1\), then the inner volume is 1 cubic centimeters and the volume of the whole box is \((1+2)(1+2)(1+2)=27\) cubic centimeters. The volume of the aluminium is 27-1=26 cubic centimeters.

Now, plug \(x=y=z=1\) and see which options yields 26: only answer choice E fits.

Answer: E.

P.S. For plug-in method it might happen that for some particular numbers more than one option may give "correct" answer. In this case just pick some other numbers and check again these "correct" options only.

Hi - can you please help me understand how you know that based on the 1cm thickness, you should expand each side x/y/z by +2?

We’ve given one of our favorite features a boost! You can now manage your profile photo, or avatar , right on WordPress.com. This avatar, powered by a service...

Sometimes it’s the extra touches that make all the difference; on your website, that’s the photos and video that give your content life. You asked for streamlined access...

A lot has been written recently about the big five technology giants (Microsoft, Google, Amazon, Apple, and Facebook) that dominate the technology sector. There are fears about the...

Post today is short and sweet for my MBA batchmates! We survived Foundations term, and tomorrow's the start of our Term 1! I'm sharing my pre-MBA notes...