An alchemist discovered that the formula to turn ordinary me : GMAT Problem Solving (PS)
Check GMAT Club Decision Tracker for the Latest School Decision Releases http://gmatclub.com/AppTrack

 It is currently 21 Jan 2017, 08:05

### GMAT Club Daily Prep

#### 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

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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# An alchemist discovered that the formula to turn ordinary me

Author Message
TAGS:

### Hide Tags

Manager
Joined: 11 Aug 2012
Posts: 128
Schools: HBS '16, Stanford '16
Followers: 1

Kudos [?]: 104 [0], given: 16

An alchemist discovered that the formula to turn ordinary me [#permalink]

### Show Tags

30 Dec 2012, 09:20
6
This post was
BOOKMARKED
00:00

Difficulty:

45% (medium)

Question Stats:

65% (02:46) correct 35% (02:01) wrong based on 115 sessions

### HideShow timer Statistics

An alchemist discovered that the formula to turn ordinary metal into gold is $$G = \frac{3}{2}M + 15$$, where G is the number of gold bars and M is the number of metal bars. If a metal bar weighs twice as much as a gold bar, how many metal bars will yield an equal weight of gold?

A. 10
B. 15
C. 22.5
D. 30
E. 67.5
[Reveal] Spoiler: OA
Manager
Joined: 05 May 2012
Posts: 67
Location: India
Concentration: General Management, Finance
GMAT 1: 670 Q48 V34
GMAT 2: 720 Q49 V40
Followers: 4

Kudos [?]: 25 [1] , given: 16

Re: An alchemist discovered that the formula to turn ordinary me [#permalink]

### Show Tags

30 Dec 2012, 11:15
1
KUDOS
best approach would be to plug in answer choices.

M=22.5
2M=45
G = 22.5*3/2+15 as it would have a fractional part.. skip it
choose a number which wont result in fractional part so A and D remains

Take D:
M=30
2M=60 which should be our target value

put M=30 we get G=60

Manager
Joined: 04 Oct 2011
Posts: 224
Location: India
GMAT 1: 440 Q33 V13
GMAT 2: 0 Q0 V0
GPA: 3
Followers: 0

Kudos [?]: 48 [0], given: 44

Re: An alchemist discovered that the formula to turn ordinary me [#permalink]

### Show Tags

09 Jan 2013, 06:36
mansoorfarooqui wrote:
best approach would be to plug in answer choices.

M=22.5
2M=45
G = 22.5*3/2+15 as it would have a fractional part.. skip it
choose a number which wont result in fractional part so A and D remains

Take D:
M=30
2M=60 which should be our target value

put M=30 we get G=60

Hey Mansoor,
"a metal bar weighs twice as much as a gold bar"
this doesnt mean
M=2G ?
_________________

GMAT - Practice, Patience, Persistence
Kudos if u like

VP
Status: Been a long time guys...
Joined: 03 Feb 2011
Posts: 1420
Location: United States (NY)
Concentration: Finance, Marketing
GPA: 3.75
Followers: 175

Kudos [?]: 1335 [1] , given: 62

Re: An alchemist discovered that the formula to turn ordinary me [#permalink]

### Show Tags

09 Jan 2013, 07:07
1
KUDOS
danzig wrote:
An alchemist discovered that the formula to turn ordinary metal into gold is $$G = \frac{3}{2}M + 15$$, where G is the number of gold bars and M is the number of metal bars. If a metal bar weighs twice as much as a gold bar, how many metal bars will yield an equal weight of gold?

A. 10
B. 15
C. 22.5
D. 30
E. 67.5

A time saving method:
Since we know that $$Integer+Integer=Integer$$, and number of bars can't be in fractional form, therefore $$3M/2$$ must be an integer or M must be a multiple of 2.
The only options that we have is A and D.
On putting 10 and 30 respectively, we find that 30 fits the conditions.
_________________
Senior Manager
Status: Final Lap
Joined: 25 Oct 2012
Posts: 287
Concentration: General Management, Entrepreneurship
GPA: 3.54
WE: Project Management (Retail Banking)
Followers: 3

Kudos [?]: 289 [0], given: 85

Re: An alchemist discovered that the formula to turn ordinary me [#permalink]

### Show Tags

09 Jan 2013, 07:39
Since a metal bar weighs twice as much as a gold bar, 2M = G

Thus, by the equation given :
2M = (3/2 *M) + 15
M/2 = 15

M = 30

Hence,

_________________

KUDOS is the good manner to help the entire community.

Manager
Joined: 28 Feb 2012
Posts: 115
GPA: 3.9
WE: Marketing (Other)
Followers: 0

Kudos [?]: 42 [0], given: 17

Re: An alchemist discovered that the formula to turn ordinary me [#permalink]

### Show Tags

10 Jan 2013, 10:38
Rock750 wrote:
Since a metal bar weighs twice as much as a gold bar, 2M = G

Thus, by the equation given :
2M = (3/2 *M) + 15
M/2 = 15

M = 30

Hence,

Well here i faced confusion, i thought if 1 bar of mettal is twice havier than 1 bar of gold, for example 1 bar of M=4 kg then 1 bar of G=2 kg, that means 4=2*2 --> M=2G but not 2M=G, So according to my initial calculation i stuck then i decided to plug in and found D plausable.

But could anyone suggest whether my initial thinking was wrong?
_________________

If you found my post useful and/or interesting - you are welcome to give kudos!

Senior Manager
Status: Final Lap
Joined: 25 Oct 2012
Posts: 287
Concentration: General Management, Entrepreneurship
GPA: 3.54
WE: Project Management (Retail Banking)
Followers: 3

Kudos [?]: 289 [0], given: 85

Re: An alchemist discovered that the formula to turn ordinary me [#permalink]

### Show Tags

10 Jan 2013, 14:17
ziko wrote:
Rock750 wrote:
Since a metal bar weighs twice as much as a gold bar, 2M = G

Thus, by the equation given :
2M = (3/2 *M) + 15
M/2 = 15

M = 30

Hence,

Well here i faced confusion, i thought if 1 bar of mettal is twice havier than 1 bar of gold, for example 1 bar of M=4 kg then 1 bar of G=2 kg, that means 4=2*2 --> M=2G but not 2M=G, So according to my initial calculation i stuck then i decided to plug in and found D plausable.

But could anyone suggest whether my initial thinking was wrong?

Did u get D using M=2G ?
_________________

KUDOS is the good manner to help the entire community.

Manager
Joined: 28 Feb 2012
Posts: 115
GPA: 3.9
WE: Marketing (Other)
Followers: 0

Kudos [?]: 42 [0], given: 17

Re: An alchemist discovered that the formula to turn ordinary me [#permalink]

### Show Tags

11 Jan 2013, 02:14
Rock750 wrote:
ziko wrote:
Rock750 wrote:
Since a metal bar weighs twice as much as a gold bar, 2M = G

Thus, by the equation given :
2M = (3/2 *M) + 15
M/2 = 15

M = 30

Hence,

Well here i faced confusion, i thought if 1 bar of mettal is twice havier than 1 bar of gold, for example 1 bar of M=4 kg then 1 bar of G=2 kg, that means 4=2*2 --> M=2G but not 2M=G, So according to my initial calculation i stuck then i decided to plug in and found D plausable.

But could anyone suggest whether my initial thinking was wrong?

Did u get D using M=2G ?

No i did not, that s why i raised this question, to clarify where i did wrong? or where exactly i am loosing the track.
_________________

If you found my post useful and/or interesting - you are welcome to give kudos!

Veritas Prep GMAT Instructor
Joined: 16 Oct 2010
Posts: 7125
Location: Pune, India
Followers: 2137

Kudos [?]: 13676 [1] , given: 222

Re: An alchemist discovered that the formula to turn ordinary me [#permalink]

### Show Tags

11 Jan 2013, 04:31
1
KUDOS
Expert's post
1
This post was
BOOKMARKED
ziko wrote:
Rock750 wrote:
Since a metal bar weighs twice as much as a gold bar, 2M = G

Thus, by the equation given :
2M = (3/2 *M) + 15
M/2 = 15

M = 30

Hence,

Well here i faced confusion, i thought if 1 bar of mettal is twice havier than 1 bar of gold, for example 1 bar of M=4 kg then 1 bar of G=2 kg, that means 4=2*2 --> M=2G but not 2M=G, So according to my initial calculation i stuck then i decided to plug in and found D plausable.

But could anyone suggest whether my initial thinking was wrong?

Notice that M is the number of metal bars (not their weight)
And G is the number of gold bars.

If weight of a metal bar is twice the weight of a gold bar, and if you want to equate their weights, you will need twice the number of gold bars to make their weights equal.

That is how you get 2M = G (Number of gold bars should be twice the number of metal bars)
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Get started with Veritas Prep GMAT On Demand for \$199

Veritas Prep Reviews

GMAT Club Legend
Joined: 09 Sep 2013
Posts: 13480
Followers: 576

Kudos [?]: 163 [0], given: 0

Re: An alchemist discovered that the formula to turn ordinary me [#permalink]

### Show Tags

22 Jun 2015, 04:36
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.
_________________
GMAT Club Legend
Joined: 09 Sep 2013
Posts: 13480
Followers: 576

Kudos [?]: 163 [0], given: 0

Re: An alchemist discovered that the formula to turn ordinary me [#permalink]

### Show Tags

28 Dec 2016, 04:19
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: An alchemist discovered that the formula to turn ordinary me   [#permalink] 28 Dec 2016, 04:19
Similar topics Replies Last post
Similar
Topics:
2 A difficult math problem, no ordinary person comes in~ 7 24 Jul 2011, 02:57
3 Word Problem, formulas 4 04 Aug 2010, 03:03
1 An alchemist discovered that the formula expressing the correct propor 1 15 Jul 2010, 11:21
1 Formula for divisors 1 16 May 2010, 00:56
56 In a certain company, the formula for maximizing profits is 18 09 Feb 2009, 02:12
Display posts from previous: Sort by