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:

In an ensemble of gongs, all gongs have a diameter of either [#permalink]
12 Nov 2009, 12:17

2

This post was BOOKMARKED

00:00

A

B

C

D

E

Difficulty:

75% (hard)

Question Stats:

61% (03:36) correct
39% (03:17) wrong based on 91 sessions

In an ensemble of gongs, all gongs have a diameter of either ten inches, or twelve inches or fifteen inches. In the collection there are 18 ten inch gongs. Half of the gongs in the collection are Tiger gongs. Of the Tiger gongs, there are equal numbers of ten inch, twelve inch and fifteen inch gongs. Half of the twelve inch gongs are not Tiger gongs, and half of all gongs are fifteen inches in diameter. How many gongs are there in the collection?

In an ensemble of gongs, all gongs have a diameter of either ten inches, or twelve inches or fifteen inches. In the collection there are 18 ten inch gongs. Half of the gongs in the collection are Tiger gongs. Of the Tiger gongs, there are equal numbers of ten inch, twelve inch and fifteen inch gongs. Half of the twelve inch gongs are not Tiger gongs, and half of all gongs are fifteen inches in diameter. How many gongs are there in the collection? 18 54 72 90 108

In an ensemble of gongs, all gongs have a diameter of either ten inches, or twelve inches or fifteen inches. In the collection there are 18 ten inch gongs. Half of the gongs in the collection are Tiger gongs. Of the Tiger gongs, there are equal numbers of ten inch, twelve inch and fifteen inch gongs. Half of the twelve inch gongs are not Tiger gongs, and half of all gongs are fifteen inches in diameter. How many gongs are there in the collection? 18 54 72 90 108

If not the wording question won't be hard:

Let x and y be 12 and 15 inches gongs respectively. We know that ten inches are 18.

1. \(18+x+y=S\). We want to calculate \(S\).

2. "Half of the gongs in the collection are Tiger gongs" --> \(2t=S\).

3. "Half of the twelve inch gongs are not Tiger gongs" --> means another half IS Tiger gongs, so x/2 is in Tiger gongs. As "Of the Tiger gongs, there are equal numbers of ten inch, twelve inch and fifteen inch gongs". --> x/2+x/2+x/2=t --> \(\frac{3}{2}x=t\)

4. "Half of all gongs are fifteen inches in diameter" --> \(2y=S\)

Four unknowns, four equations.

(3) \(\frac{3}{2}x=t\) and (2) \(2t=S\) --> \(x=\frac{S}{3}\)

The only use I got from the Kaplan premier book is to find the best way to answer such questions. I will use different tables for the purpose of explanation but you would need just 1. We will try and create a Sum table based on the given information. You should start of like this - Diameter of gong along the horizontal axis & type of gong along the vertical axis. Also let the total number of gongs = x, we need to find x. 10 12 15 TG

NTG x TG = Tiger Gong, NTG is the non tiger gong. Lets start filling this table up with the pieces of info given 1) In the collection there are 18 ten inch gongs 10 12 15 TG

NTG 18 x 2) Half of the gongs in the collection are Tiger gongs. 10 12 15 TG x/2

NTG =x-x/2 = x/2 18 x 3) Of the Tiger gongs, there are equal numbers of ten inch, twelve inch and fifteen inch gongs. 10 12 15 TG x/6 x/6 x/6 x/2

NTG x/2 18 x 4) Half of the twelve inch gongs are not Tiger gongs. 10 12 15 TG x/6 x/6 x/6 x/2

NTG x/6 x/2 18 x 5) half of all gongs are fifteen inches in diameter 10 12 15 TG x/6 x/6 x/6 x/2

NTG x/6 x/2 18 x/2 x

now we have enough info to solve the problem - total number of 12 inch gongs = x/6+x/6=x/3 now we equate the bottom horizontal row i.e. 18 + x/3 +x/2 = x x = 18*6 = 108.

In an ensemble of gongs, all gongs have a diameter of either ten inches, or twelve inches or fifteen inches. In the collection there are 18 ten inch gongs. Half of the gongs in the collection are Tiger gongs. Of the Tiger gongs, there are equal numbers of ten inch, twelve inch and fifteen inch gongs. Half of the twelve inch gongs are not Tiger gongs, and half of all gongs are fifteen inches in diameter. How many gongs are there in the collection? 18 54 72 90 108

If not the wording question won't be hard:

Let x and y be 12 and 15 inches gongs respectively. We know that ten inches are 18.

1. \(18+x+y=S\). We want to calculate \(S\).

2. "Half of the gongs in the collection are Tiger gongs" --> \(2t=S\).

3. "Half of the twelve inch gongs are not Tiger gongs" --> means another half IS Tiger gongs, so x/2 is in Tiger gongs. As "Of the Tiger gongs, there are equal numbers of ten inch, twelve inch and fifteen inch gongs". --> x/2+x/2+x/2=t --> \(\frac{3}{2}x=t\)

4. "Half of all gongs are fifteen inches in diameter" --> \(2y=S\)

Four unknowns, four equations.

(3) \(\frac{3}{2}x=t\) and (2) \(2t=S\) --> \(x=\frac{S}{3}\)

Hey bunuel I got this question by an easy approach Let total gongs be G and tiger gongs be T so T=G/2 now as the question says there is a equal no of tiger gongs in each catagory hence T/3 each now it has been given in the question that gongs that have 10 inches Diameter are 18 in nos so T/3 = 18 so T =54 now T=G/2 so 54 = G/2 so G=108

it was quite easy this way just tell me if I am wrong.......... Regards Puneet Sharma [WarLocK] _________________

WarLocK _____________________________________________________________________________ The War is oNNNNNNNNNNNNN for 720+ see my Test exp here http://gmatclub.com/forum/my-test-experience-111610.html do not hesitate me giving kudos if you like my post.

In an ensemble of gongs, all gongs have a diameter of either ten inches, or twelve inches or fifteen inches. In the collection there are 18 ten inch gongs. Half of the gongs in the collection are Tiger gongs. Of the Tiger gongs, there are equal numbers of ten inch, twelve inch and fifteen inch gongs. Half of the twelve inch gongs are not Tiger gongs, and half of all gongs are fifteen inches in diameter. How many gongs are there in the collection? 18 54 72 90 108

Let x be the number of ten inch, twelve inch and fifteen inch Tiger gongs, so total number of tiger gongs is 3x and total number of gongs is 6x.

Now half of all gongs are fifteen inches in diameter so they must number 3x and hence there are 2x fifteen inches non Tiger gongs.

Also, Half of the twelve inch gongs are not Tiger gongs so there are x twelve inches non Tiger gongs.

Therefore, all the non Tiger gongs (3x) are fifteen inches (2x) or twelve inches (x)

Thus, all the 18 inch gongs are tiger gongs and hence x=18, so total gongs is 6*18 = 108.

In an ensemble of gongs, all gongs have a diameter of either ten inches, or twelve inches or fifteen inches. In the collection there are 18 ten inch gongs. Half of the gongs in the collection are Tiger gongs. Of the Tiger gongs, there are equal numbers of ten inch, twelve inch and fifteen inch gongs. Half of the twelve inch gongs are not Tiger gongs, and half of all gongs are fifteen inches in diameter. How many gongs are there in the collection? 18 54 72 90 108

If not the wording question won't be hard:

Let x and y be 12 and 15 inches gongs respectively. We know that ten inches are 18.

1. \(18+x+y=S\). We want to calculate \(S\).

2. "Half of the gongs in the collection are Tiger gongs" --> \(2t=S\).

3. "Half of the twelve inch gongs are not Tiger gongs" --> means another half IS Tiger gongs, so x/2 is in Tiger gongs. As "Of the Tiger gongs, there are equal numbers of ten inch, twelve inch and fifteen inch gongs". --> x/2+x/2+x/2=t --> \(\frac{3}{2}x=t\)

4. "Half of all gongs are fifteen inches in diameter" --> \(2y=S\)

Four unknowns, four equations.

(3) \(\frac{3}{2}x=t\) and (2) \(2t=S\) --> \(x=\frac{S}{3}\)

Hey bunuel I got this question by an easy approach Let total gongs be G and tiger gongs be T so T=G/2 now as the question says there is a equal no of tiger gongs in each catagory hence T/3 each now it has been given in the question that gongs that have 10 inches Diameter are 18 in nos so T/3 = 18 so T =54 now T=G/2 so 54 = G/2 so G=108

it was quite easy this way just tell me if I am wrong.......... Regards Puneet Sharma [WarLocK]

This is incorrect. You cannot say T/3 = 18. T is only tiger gongs and T/3 is tiger gongs (10in). We dont know if this is 18. 18 is the total nnumber of 10in gongs.

Re: In an ensemble of gongs, all gongs have a diameter of either [#permalink]
19 Mar 2014, 05:20

There are 18 of the ten inch gongs, and we also know that there are some that are tiger gongs those are equally distributed among the three types. Now, since half of them are tiger gongs and of them 1/3 are 12 inch gongs, then 12 inch gongs are 1/6X, were X represents the total number of gongs. Now we are told that the 15 inch are the remainder. Therefore we know that x/2 + x/6 = 5/6 x, so 15 inch must be 1/6x = 18, therefore x=108. Answer is E.

Hope this clarifies Cheers J

gmatclubot

Re: In an ensemble of gongs, all gongs have a diameter of either
[#permalink]
19 Mar 2014, 05:20

On September 6, 2015, I started my MBA journey at London Business School. I took some pictures on my way from the airport to school, and uploaded them on...

When I was growing up, I read a story about a piccolo player. A master orchestra conductor came to town and he decided to practice with the largest orchestra...

Last week, hundreds of first-year and second-year students traversed the globe as part of KWEST: Kellogg Worldwide Experience and Service Trip. Kyle Burr, one of the student-run KWEST executive...