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 350,000 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 specialized type of sand consists of 40% mineral X by volu [#permalink]
02 Oct 2011, 13:28

1

This post received KUDOS

2

This post was BOOKMARKED

00:00

A

B

C

D

E

Difficulty:

65% (hard)

Question Stats:

66% (02:34) correct
34% (01:49) wrong based on 224 sessions

A specialized type of sand consists of 40% mineral X by volume and 60% mineral Y by volume. If mineral X weighs 2.5 grams per cubic centimeter and mineral Y weighs 3 grams per cubic centimeter, how many grams does a cubic meter of specialized sand combination weigh? (1 meter = 100 centimeters)

A. 5,500,000 B. 2,800,000 C. 55,000 D. 28,000 E. 280

Re: Specialized sand combination... [#permalink]
03 Oct 2011, 08:38

5

This post received KUDOS

Expert's post

martie11 wrote:

A specialized type of sand consists of 40% mineral X by volume and 60% mineral Y by volume. If mineral X weighs 2.5 grams per cubic centimeter and mineral Y weighs 3 grams per cubic centimeter, how many grams does a cubic meter of specialized sand combination weigh? (1 meter = 100 centimeters)

a) 5,500,000 b) 2,800,000 c) 55,000 d) 28,000 e) 280

Good luck...cheers.

Let me share what goes through my mind here to arrive at the answer orally: Volume of mineral X is 40% and that of mineral Y is 60% i.e. they are in the ratio 2:3. So if we have 2 \(cm^3\) of X, we have 3 \(cm^3\) of Y. Weight of X is 2.5 gms/\(cm^3\) so weight of 2 \(cm^3\) of X is 5 gm Weight of Y is 3 gms/\(cm^3\) so weight of 3 \(cm^3\) of Y is 9 gm therefore, weight of 5 \(cm^3\) of mixture is 14 gm So weight of 10 \(cm^3\) of mixture is 28 gm Since 1 \(m^3\) = 1,000,000 \(cm^3\), weight of 1,000,000 \(cm^3\) of mixture must be 2,800,000 gms _________________

Re: Specialized sand combination... [#permalink]
03 Oct 2011, 01:00

3

This post received KUDOS

Let the volume be 1 m^3 = 1m * 1m * 1m = 100cm * 100cm * 100cm = 1,000,000 cm^3 By volume 40% is X = 400,000 cm^3 60% is Y = 600,000 cm^3

By weight, In 1 cm^3, X is 2.5 gms In 400,000 cm^3 , X = 2.5 * 400,000 = 1,000,000 gms In 1 cm^3, Y is 3 gms In 600,000 cm^3, Y = 3 * 600,000 = 1,800,000 gms Total gms in 1 m^3 = 1,000,000 + 1,800,000 = 2,800,000

OA B. _________________

My dad once said to me: Son, nothing succeeds like success.

Re: Specialized sand combination... [#permalink]
03 Oct 2011, 04:43

1

This post received KUDOS

martie11 wrote:

A specialized type of sand consists of 40% mineral X by volume and 60% mineral Y by volume. If mineral X weighs 2.5 grams per cubic centimeter and mineral Y weighs 3 grams per cubic centimeter, how many grams does a cubic meter of specialized sand combination weigh? (1 meter = 100 centimeters)

a) 5,500,000 b) 2,800,000 c) 55,000 d) 28,000 e) 280

Good luck...cheers.

1 cubic cm = 0.4 x 2.5 + 0.6 x 3 = 2.8g 1000000 cubic cm = 1 cubic m = 2.8 x 10^6 (B) _________________

Re: Specialized sand combination... [#permalink]
25 Mar 2013, 09:19

1

This post received KUDOS

Expert's post

mahendru1992 wrote:

hey karishma, can this question be done using your method of weighted averages? I'm trying to do the question using weighted averages but am not able to. Your help would be appreciated.

Yes, you can.

Weight of X is 2.5 gms/\(cm^3\) Weight of Y is 3 gms/\(cm^3\) Weight of a mixture of X and Y such that they are in the ratio 40%:60% i.e. 2:3 will be Wavg.

Note: If you notice carefully, you don't need to do this calculation. The Wavg will lie between 2.5 and 3. Also, Wavg will be in units of gms/\(cm^3\) so you will need to multiply it by 1,000,000 to convert to gms/\(m^3\). Hence, only suitable answer will be 2.8*1,000,000 _________________

Re: Specialized sand combination... [#permalink]
03 Oct 2011, 03:34

martie11 wrote:

A specialized type of sand consists of 40% mineral X by volume and 60% mineral Y by volume. If mineral X weighs 2.5 grams per cubic centimeter and mineral Y weighs 3 grams per cubic centimeter, how many grams does a cubic meter of specialized sand combination weigh? (1 meter = 100 centimeters)

a) 5,500,000 b) 2,800,000 c) 55,000 d) 28,000 e) 280

OA to follow

Good luck...cheers.

1 m^3= (100)^3 cm^3

So, 3 gram in 1 cm^3; Y=3*(100)^3 gram in (100)^3 cm^3 OR 1 m^3

Likewise, 2.5 gram in 1 cm^3; X=2.5*(100)^3 gram in (100)^3 cm^3 OR 1 m^3

Re: Specialized sand combination... [#permalink]
25 Mar 2013, 06:45

VeritasPrepKarishma wrote:

martie11 wrote:

A specialized type of sand consists of 40% mineral X by volume and 60% mineral Y by volume. If mineral X weighs 2.5 grams per cubic centimeter and mineral Y weighs 3 grams per cubic centimeter, how many grams does a cubic meter of specialized sand combination weigh? (1 meter = 100 centimeters)

a) 5,500,000 b) 2,800,000 c) 55,000 d) 28,000 e) 280

Good luck...cheers.

Let me share what goes through my mind here to arrive at the answer orally: Volume of mineral X is 40% and that of mineral Y is 60% i.e. they are in the ratio 2:3. So if we have 2 \(cm^3\) of X, we have 3 \(cm^3\) of Y. Weight of X is 2.5 gms/\(cm^3\) so weight of 2 \(cm^3\) of X is 5 gm Weight of Y is 3 gms/\(cm^3\) so weight of 3 \(cm^3\) of Y is 9 gm therefore, weight of 5 \(cm^3\) of mixture is 14 gm So weight of 10 \(cm^3\) of mixture is 28 gm Since 1 \(m^3\) = 1,000,000 \(cm^3\), weight of 1,000,000 \(cm^3\) of mixture must be 2,800,000 gms

hey karishma, can this question be done using your method of weighted averages? I'm trying to do the question using weighted averages but am not able to. Your help would be appreciated.

Re: A specialized type of sand consists of 40% mineral X by volu [#permalink]
25 Mar 2013, 21:58

Thanks for the quick reply Karishma! Now i'm digressing from the topic, but I want your advice on the 700 level questions. No matter what topic I pick-up, i usually end up doing those questions wrong or having no idea as to how to go about them. Is there some specific stratergy or technique involved or should I just keep on practicing?

Re: A specialized type of sand consists of 40% mineral X by volu [#permalink]
27 Mar 2013, 19:42

Expert's post

mahendru1992 wrote:

Thanks for the quick reply Karishma! Now i'm digressing from the topic, but I want your advice on the 700 level questions. No matter what topic I pick-up, i usually end up doing those questions wrong or having no idea as to how to go about them. Is there some specific stratergy or technique involved or should I just keep on practicing?

The thing about 700+ level questions is that you need to be more innovative in them. You need to think of all that you know in Quant and link it up - i.e. focusing on one topic (on which the question seems to be based) is not enough. As an example, check out this question I made for Veritas some time back.

"After multiplying a positive integer A, which has n digits, by (n+2), we get a number with (n+1) digits, all of whose digits are (n+1). How many instances of A exist?"

What do you think it tests? By just reading the question, you cannot guess that all you need to know to solve it within one minute are your divisibility rules. Also, you need to start with whatever is definitive. Check out this link for the solution (after-multiplying-a-positive-integer-a-which-has-n-digits-147350.html#p1183033)

700+ level questions use the same fundamentals but are harder because of the way the question is worded. Practice high level questions and check out every different method available to solve them. You can use methods learned in one topic to solve questions of another if you can just identify the parallel. e.g. check out this post where I solve a permutations question using sets (method 2) http://www.veritasprep.com/blog/2012/01 ... e-couples/

The more exposed you are to high level questions, the more intuitive they will get with time. _________________

Re: A specialized type of sand consists of 40% mineral X by volu [#permalink]
23 Jun 2013, 20:30

1. We need to find the weight of a certain mix. 2. The mix is 40% x and 60% y. The volume of the mix for which we need to find the weight is 1 cubic meter 3. 1 cubic meter of the mix contains 0.4 cu.m of x and 0.6 cu.m of y. 4. Weight of 1 cubic meter of x is 2500000g and weight of 1 cubic meter of y is 3000000g 5. So weight of 0.4 cubic meter of x is 1000000g and weight of 0.6 cubic meter of y is 1800000g 6. Total weight of 1 cubic meter of the mix is 2,800,000g _________________

Re: A specialized type of sand consists of 40% mineral X by volu [#permalink]
10 Jun 2015, 22:42

Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email. _________________

Hey, everyone. After a hectic orientation and a weeklong course, Managing Groups and Teams, I have finally settled into the core curriculum for Fall 1, and have thus found...

MBA Acceptance Rate by Country Most top American business schools brag about how internationally diverse they are. Although American business schools try to make sure they have students from...

After I was accepted to Oxford I had an amazing opportunity to visit and meet a few fellow admitted students. We sat through a mock lecture, toured the business...