GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 23 Sep 2019, 04:26 ### 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

#### Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here. ### Request Expert Reply # 1 unit of x% alcohol is mixed with 3 units of y% alcohol to give 60%

 new topic post reply Question banks Downloads My Bookmarks Reviews Important topics
Author Message
TAGS:

### Hide Tags

General GMAT Forum Moderator V
Joined: 15 Jan 2018
Posts: 550
Concentration: General Management, Finance
GMAT 1: 720 Q50 V37 1 unit of x% alcohol is mixed with 3 units of y% alcohol to give 60%  [#permalink]

### Show Tags

1
8 00:00

Difficulty:   95% (hard)

Question Stats: 33% (03:20) correct 67% (02:45) wrong based on 51 sessions

### HideShow timer Statistics

1 unit of x% alcohol is mixed with 3 units of y% alcohol to give 60% alcohol. If x > y, how many integer values can x take?

A. 10
B. 20
C. 35
D. 13
E. 30

_________________
In case you find my post helpful, please provide me with kudos. Thank you!

New to GMAT Club or overwhelmed with so many resources? Follow the GMAT Club Study Plan!
Not happy with your GMAT score? Retaking GMAT Strategies!
Director  D
Joined: 19 Oct 2018
Posts: 880
Location: India
Re: 1 unit of x% alcohol is mixed with 3 units of y% alcohol to give 60%  [#permalink]

### Show Tags

3
x.........y
....60....
1.........3

$$\frac{x-60}{60-y}$$=3/1
x+3y=240...(1)
x=240-3y=3(80-y)

We have 2 constraints
1. x=<100
2. x>y
Also, x will be a multiple of 3

x can be 99,96.....63
At x=60, y=60....Hence x can't take value equal to 60 or lower than 60.
Total number of integer values x can take= [$$\frac{99-63}{3}$$]+1=13

DisciplinedPrep wrote:
1 unit of x% alcohol is mixed with 3 units of y% alcohol to give 60% alcohol. If x > y, how many integer values can x take?

A. 10
B. 20
C. 35
D. 13
E. 30
##### General Discussion
Manager  S
Joined: 25 Mar 2018
Posts: 73
Location: India
Schools: ISB '21, IIMA , IIMB
GMAT 1: 650 Q50 V28 GPA: 4
WE: Analyst (Manufacturing)
Re: 1 unit of x% alcohol is mixed with 3 units of y% alcohol to give 60%  [#permalink]

### Show Tags

2
Question is clear but OA is surprising.

The equation on which question depends is

x + 3y = 4*60

So we can start x with 61, which is integer value. We don't bother about Y. Y can take any value integer or not.

So IMHO answer is (100-61)+1 , which is 40.

Posted from my mobile device
_________________
Please give me +1 kudos if my post helps you a little. It will help me unlock tests. Thanks
Veritas Prep GMAT Instructor D
Joined: 16 Oct 2010
Posts: 9648
Location: Pune, India
Re: 1 unit of x% alcohol is mixed with 3 units of y% alcohol to give 60%  [#permalink]

### Show Tags

1
DisciplinedPrep wrote:
1 unit of x% alcohol is mixed with 3 units of y% alcohol to give 60% alcohol. If x > y, how many integer values can x take?

A. 10
B. 20
C. 35
D. 13
E. 30

1 part x% alcohol + 3 parts y% alcohol -> 60% alcohol

Since x > y, x must be greater than 60% and y must be less than 60% so that they average out to 60.
The maximum value of x can be 100% (the entire solution can be alcohol).
So x can take any integer value from 61 to 100.

But it seems that the intent of the question is that x and y both should be integer values.

y --- 60 --------- x

Since we are mixing 1 part x with 3 parts y, average will be 1 unit away from y and 3 units away from x.
So if y = 59, x = 63
if y = 58, x = 66
and so on...
x will take values from 63% to 99% i.e. (3*21) to (3*33)
This means (33 - 21 = )12 + 1 = 13 multiples of 3

Check this post for the scale method of weighted avgs:
https://www.veritasprep.com/blog/2011/0 ... -averages/
_________________
Karishma
Veritas Prep GMAT Instructor

Learn more about how Veritas Prep can help you achieve a great GMAT score by checking out their GMAT Prep Options >
Intern  B
Joined: 15 Jan 2019
Posts: 37
Location: India
GMAT 1: 650 Q42 V32 Re: 1 unit of x% alcohol is mixed with 3 units of y% alcohol to give 60%  [#permalink]

### Show Tags

nick1816 wrote:
x.........y
....60....
1.........3

$$\frac{x-60}{60-y}$$=3/1
x+3y=240...(1)
x=240-3y=3(80-y)

We have 2 constraints
1. x=<100
2. x>y
Also, x will be a multiple of 3

x can be 99,96.....63
At x=60, y=60....Hence x can't take value equal to 60 or lower than 60.
Total number of integer values x can take= [$$\frac{99-63}{3}$$]+1=13

DisciplinedPrep wrote:
1 unit of x% alcohol is mixed with 3 units of y% alcohol to give 60% alcohol. If x > y, how many integer values can x take?

A. 10
B. 20
C. 35
D. 13
E. 30

I don't get it. x and y are concentration in percent. 3 and 1 are the value of units.
the 2 equations will be
1x + 3y = ?
x+y=60.

So we have to find to the value of x for which it is greater than y and the first equation gives a valid number.
right?
Manager  B
Joined: 11 Aug 2017
Posts: 61
Re: 1 unit of x% alcohol is mixed with 3 units of y% alcohol to give 60%  [#permalink]

### Show Tags

nick1816 wrote:
x.........y
....60....
1.........3

$$\frac{x-60}{60-y}$$=3/1
x+3y=240...(1)
x=240-3y=3(80-y)

We have 2 constraints
1. x=<100
2. x>y
Also, x will be a multiple of 3

x can be 99,96.....63
At x=60, y=60....Hence x can't take value equal to 60 or lower than 60.
Total number of integer values x can take= [$$\frac{99-63}{3}$$]+1=13

DisciplinedPrep wrote:
1 unit of x% alcohol is mixed with 3 units of y% alcohol to give 60% alcohol. If x > y, how many integer values can x take?

A. 10
B. 20
C. 35
D. 13
E. 30

Why x has to be less than or equ. 100? i could not understand. please guide??
Manager  S
Joined: 01 Oct 2018
Posts: 112
Re: 1 unit of x% alcohol is mixed with 3 units of y% alcohol to give 60%  [#permalink]

### Show Tags

Mohammad Ali Khan wrote:
nick1816 wrote:
x.........y
....60....
1.........3

$$\frac{x-60}{60-y}$$=3/1
x+3y=240...(1)
x=240-3y=3(80-y)

We have 2 constraints
1. x=<100
2. x>y
Also, x will be a multiple of 3

x can be 99,96.....63
At x=60, y=60....Hence x can't take value equal to 60 or lower than 60.
Total number of integer values x can take= [$$\frac{99-63}{3}$$]+1=13

DisciplinedPrep wrote:
1 unit of x% alcohol is mixed with 3 units of y% alcohol to give 60% alcohol. If x > y, how many integer values can x take?

A. 10
B. 20
C. 35
D. 13
E. 30

Why x has to be less than or equ. 100? i could not understand. please guide??

Maximum value of aclhogol in unit is 100% Re: 1 unit of x% alcohol is mixed with 3 units of y% alcohol to give 60%   [#permalink] 12 Jun 2019, 17:51
Display posts from previous: Sort by

# 1 unit of x% alcohol is mixed with 3 units of y% alcohol to give 60%

 new topic post reply Question banks Downloads My Bookmarks Reviews Important topics

 Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne  