Last visit was: 16 May 2025, 13:02 It is currently 16 May 2025, 13:02
Close
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
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.
Close
Request Expert Reply
Confirm Cancel
605-655 Level|   Math Related|               
User avatar
parkhydel
Joined: 03 Jun 2019
Last visit: 27 Mar 2025
Posts: 214
Own Kudos:
16,230
 [80]
Given Kudos: 60
Posts: 214
Kudos: 16,230
 [80]
6
Kudos
Add Kudos
74
Bookmarks
Bookmark this Post
Most Helpful Reply
User avatar
Sajjad1994
User avatar
GRE Forum Moderator
Joined: 02 Nov 2016
Last visit: 16 May 2025
Posts: 15,127
Own Kudos:
44,953
 [8]
Given Kudos: 6,027
GPA: 3.62
Products:
Posts: 15,127
Kudos: 44,953
 [8]
4
Kudos
Add Kudos
3
Bookmarks
Bookmark this Post
User avatar
KarishmaB
Joined: 16 Oct 2010
Last visit: 16 May 2025
Posts: 15,969
Own Kudos:
73,140
 [6]
Given Kudos: 468
Location: Pune, India
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 15,969
Kudos: 73,140
 [6]
4
Kudos
Add Kudos
2
Bookmarks
Bookmark this Post
User avatar
chetan2u
User avatar
GMAT Expert
Joined: 02 Aug 2009
Last visit: 28 Apr 2025
Posts: 11,309
Own Kudos:
40,619
 [2]
Given Kudos: 333
Status:Math and DI Expert
Products:
Expert
Expert reply
Posts: 11,309
Kudos: 40,619
 [2]
1
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
Since all bars have identical weight and it speaks of average finesse, the question can be solved through weighted average method.

Let the weight be x each, so the ratio of those with higher finesse and lowers finesse will be (x+x):x or 2:1

Thus, the finesse too should be in the same ratio. The distance between the lower finesse and 0.96 should be two times that between higher and 0.96

So, one has to be higher: If it is next higher from 0.96, then 0.98, so (0.98-0.96)=1/2 * (0.96-y)….2*0.02 = 0.96-y
Or y=0.92
General Discussion
User avatar
Apt0810
Joined: 15 Jul 2018
Last visit: 24 Oct 2020
Posts: 338
Own Kudos:
557
 [3]
Given Kudos: 94
Posts: 338
Kudos: 557
 [3]
1
Kudos
Add Kudos
2
Bookmarks
Bookmark this Post
Weight of gold in 1st and 2nd = x
Since finesse is equal for both
Weight of gold in 3rd bar = y

Total weight of each is =w

Now if they are melted and turned into one bar, resulting finesse is

2x+y/3w = 0.96
2x/w + y/w = 0.96*3
2x/w + y/w = 2.88

Now putting the above options in the equation,so

2*.98+0.92=2.88
So finesse of first and second is 0.98

Finesse of third is 0.92

Posted from my mobile device
User avatar
mSKR
Joined: 14 Aug 2019
Last visit: 10 Mar 2024
Posts: 1,312
Own Kudos:
917
 [2]
Given Kudos: 381
Location: Hong Kong
Concentration: Strategy, Marketing
GMAT 1: 650 Q49 V29
GPA: 3.81
GMAT 1: 650 Q49 V29
Posts: 1,312
Kudos: 917
 [2]
Kudos
Add Kudos
2
Bookmarks
Bookmark this Post
Total 0.96*3 = 2.88 (total finness)
2X+Y = 2.88

Prethinking:
Option1: 2 numbers closure above 0.96 and 3rd one far below 0.96 OR
option2: 2 numbers very near below 0.96 and 3rd one should be much higher than 0.96)

As per all options given higher than 0.96 is very close so it maybe possible than 2 numbers are higher than 0.96 so i chose first nearby option value above 0.96 for X i.e. 0.98 for X

Try Y= 0.98 then Y comes out to be 0.92

A quick check on our answer:
Try X = 0.99 then Y should be 0.90 - not available( Prethinking: option1)
Try Y = 0.98 then X should be 0.95*2 - not available( Prethinking: option2)
User avatar
Kartik2121
Joined: 16 Jan 2023
Last visit: 10 May 2025
Posts: 48
Own Kudos:
19
 [4]
Given Kudos: 70
GMAT Focus 1: 645 Q82 V85 DI78
GMAT 1: 620 Q44 V31
GMAT 2: 680 Q47 V37
GMAT Focus 1: 645 Q82 V85 DI78
GMAT 2: 680 Q47 V37
Posts: 48
Kudos: 19
 [4]
2
Kudos
Add Kudos
2
Bookmarks
Bookmark this Post
This one can be solved pretty quickly using the alligation method. Here is how it can be done:


The average finesse is 0.96. So the value of individual finesse of the two blocks has to be either higher than the average or lower than the average.

The same can be said about the value of finesse of the 3rd bar as well.


Now as there are two gold bars with equal finesse, we can deduce that their impact on the average shall be twice the impact of the 3rd bar. So, the 3rd bar shall be twice as far from the average finesse value as the finesse value of the two bars.

Thus, we are left with only two choices:

Either the finesse of two bars is 0.98 or 0.94 and that of 3rd bar is then 0.92 or 1.00 respectively.

The answer choices are pretty clear:

We have no 1.00. Thus, 0.94 for two bars and 1.00 for 3rd bar is out.

We are left with only one situation:

The finesse value for two bars is 0.98 and that of third bar is 0.92.

Posted from my mobile device
User avatar
sayan640
Joined: 29 Oct 2015
Last visit: 15 May 2025
Posts: 1,208
Own Kudos:
Given Kudos: 780
GMAT 1: 570 Q42 V28
Products:
GMAT 1: 570 Q42 V28
Posts: 1,208
Kudos: 683
Kudos
Add Kudos
Bookmarks
Bookmark this Post
KarishmaB chetan2u GMATinsight , Would you like to discuss this question ?­ I derived the equation but could not figure out the value.
User avatar
Gemmie
Joined: 19 Dec 2021
Last visit: 06 Apr 2025
Posts: 507
Own Kudos:
316
 [4]
Given Kudos: 76
Location: Viet Nam
Concentration: Technology, Economics
GMAT Focus 1: 695 Q87 V84 DI83
GPA: 3.55
GMAT Focus 1: 695 Q87 V84 DI83
Posts: 507
Kudos: 316
 [4]
3
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
­Third bar                           First two bars
1                                      2
[y]------------------96---------[x]
          2a                  a

x > 96
From the answer choices, x is either 98 or 99

If x = 99 => a = 3 => y = 96 - 2a = 90 => not an answer choice
If x = 98 => a = 2 => y = 96 - 2a = 92 => Ok

First two bars: x = 0.98
Third bar: y = 0.92­
User avatar
Dbrunik
Joined: 13 Apr 2024
Last visit: 16 Feb 2025
Posts: 279
Own Kudos:
Given Kudos: 267
Location: United States (MN)
Concentration: Finance, Technology
GMAT Focus 1: 625 Q84 V82 DI77
GMAT Focus 1: 625 Q84 V82 DI77
Posts: 279
Kudos: 98
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Very high-quality challenging question

Posted from my mobile device
User avatar
nikitathegreat
Joined: 16 Dec 2021
Last visit: 16 May 2025
Posts: 194
Own Kudos:
Given Kudos: 92
Location: India
GMAT 1: 630 Q45 V31
Products:
GMAT 1: 630 Q45 V31
Posts: 194
Kudos: 18
Kudos
Add Kudos
Bookmarks
Bookmark this Post
I have understood the ratio bit of the two bars that have identical weight: third bar will have ratio 1:2. But then how are we finding the values? Can someone provide step by step process for this?

Two bars ------------------------third bar
Weight = 2 weight = 1
Ratio = 1:2

How are we finding the finesses now with these values?
Thanks
User avatar
nikiki
Joined: 07 May 2023
Last visit: 16 May 2025
Posts: 70
Own Kudos:
Given Kudos: 87
Location: India
Products:
Posts: 70
Kudos: 57
Kudos
Add Kudos
Bookmarks
Bookmark this Post
We can solve it with the table we use for mixture problems


Finesse = \(\frac{ Weight of gold}{Total Weight}\)

Finesse * Total Weight = Weight of gold


FinesseTotal WeightWeight of Gold
Bar 1F1WF1 * W
Bar 2F1WF1 * W
Bar 3F2WF2 * W
0.963W2F1*W + F2*W

0.96 * 3W = 2F1*W + F2*W
2F1 + F2 = 2.88

After some trial and error we get
F1 = 0.98
F2 = 0.92



parkhydel
The finesse of a gold bar is the weight of the gold present in the bar divided by the total weight of the bar. A jeweler has three gold bars. The three bars have identical weights, and the first two bars have identical finesse. If all three bars were melted and combined into one bar, the finesse of the resulting bar would be 0.96.

Select a finesse of the First two bars and a finesse of the Third bar that are jointly consistent with the given information. Make only two selections, one in each column.­

ID: 100426
Moderators:
Math Expert
101464 posts
GMAT Expert
11309 posts
DI Forum Moderator
693 posts