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:

S2: By weight the alloy is 6 parts lead and 5 parts copper Alloy is y parts T x be the multiplier 6x+5x+yx=56 11x+yx=56 y,x can have many values. Not sufficient.

A certain alloy contains Lead , copper and tin. how many pounds of tin are in 56 pounds of the alloy

S1 By weight the alloy is 3/7 lead and 5/14 copper

S2 By weight the alloy is 6 parts lead and 5 parts copper

A certain alloy contains Lead , copper and tin. How many pounds of tin are in 56 pounds of the alloy?

(1) By weight the alloy is 3/7 lead and 5/14 copper --> by weight tin will be 1-(3/7+5/14)=3/14 of the alloy, thus there are 56*3/14=12 pounds of tin in the alloy. Sufficient.

(2) By weight the alloy is 6 parts lead and 5 parts copper. Clearly insufficient: for example tin could be 9 parts (45% of 56 pounds) or 89 part (89% of 56 pounds). Not sufficient.

Please explain this, especially the underlined portion :

By weight the alloy is 6 parts lead and 5 parts copper. Clearly insufficient: for example tin could be 9 parts (45% of 56 pounds) or 89 part (89% of 56 pounds).

Regards, Subhash _________________

Formula of Life -> Achievement/Potential = k * Happiness (where k is a constant)

Please explain this, especially the underlined portion :

By weight the alloy is 6 parts lead and 5 parts copper. Clearly insufficient: for example tin could be 9 parts (45% of 56 pounds) or 89 part (89% of 56 pounds).

Regards, Subhash

"By weight the alloy is 6 parts lead and 5 parts copper" means that the ratio lead/copper=6/5, as we don't know how many parts of tin are there then we can not find weight of each. Consider examples: if lead/copper/tin=6/5/9 --> total 20 parts --> tin=9/20=45% of 56 pounds or if lead/copper/tin=6/5/89 --> total 100 parts --> tin=89/100=89% of 56 pounds. _________________

Please explain this, especially the underlined portion :

By weight the alloy is 6 parts lead and 5 parts copper. Clearly insufficient: for example tin could be 9 parts (45% of 56 pounds) or 89 part (89% of 56 pounds).

Regards, Subhash

If Tin is 9 Parts; then the alloy will be 9 Part TIN+ 6 Parts Lead+ 5 Parts copper = 20 Tin's presence in the alloy will be: 9/20*100 = 45% (45% of the 56 lbs alloy is TIN = 56*45/100 = 25.2 lbs will be TIN)

If Tin is 89 Parts; then the alloy will be 89 Part TIN+ 6 Parts Lead+ 5 Parts copper = 100 Tin's presence in the alloy will be: 89/100*100 = 89% (89% of the 56 lbs alloy is TIN = 56*89/100 = 49.84lbs will be TIN)

Likewise; there will be infinitely many possibilities for TIN's weight in the alloy and exact weight of Tin can't be determined. _________________

Re: A certain alloy contains Lead, copper and tin. How many poun [#permalink]

Show Tags

24 Sep 2013, 18:43

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. _________________

Re: A certain alloy contains Lead, copper and tin. How many poun [#permalink]

Show Tags

28 Nov 2014, 23:30

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. _________________

So, my final tally is in. I applied to three b schools in total this season: INSEAD – admitted MIT Sloan – admitted Wharton – waitlisted and dinged No...

HBS alum talks about effective altruism and founding and ultimately closing MBAs Across America at TED: Casey Gerald speaks at TED2016 – Dream, February 15-19, 2016, Vancouver Convention Center...

By Libby Koerbel Engaging a room of more than 100 people for two straight hours is no easy task, but the Women’s Business Association (WBA), Professor Victoria Medvec...