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

 It is currently 18 Aug 2018, 05:25

### 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

# M19-25

Author Message
TAGS:

### Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 47981

### Show Tags

16 Sep 2014, 01:06
00:00

Difficulty:

25% (medium)

Question Stats:

72% (01:19) correct 28% (01:25) wrong based on 175 sessions

### HideShow timer Statistics

A shop sells candy bars individually or in packs of 10. If the shop charges less for purchasing a pack of 10 candy bars than for purchasing 10 candy bars individually, then how much does the shop charge for purchasing a pack of 10 candy bars?

(1) The charge for purchasing a pack of 10 candy bars is $2 more than the charge for purchasing the 8 candy bars. (2) The charge for purchasing a pack of 10 candy bars is 10 percent less than the charge for purchasing the 10 candy bars individually. _________________ Math Expert Joined: 02 Sep 2009 Posts: 47981 Re M19-25 [#permalink] ### Show Tags 16 Sep 2014, 01:06 Official Solution: Say the price for purchasing a pack of 10 candy bars is $$x$$ and the price for purchasing the candy bar individually is $$y$$. (1) The charge for purchasing a pack of 10 candy bars is$2 more than the charge for purchasing the 8 candy bars. Given: $$x=8y+2$$. Two unknowns one equation. Not sufficient to calculate $$x$$.

(2) The charge for purchasing a pack of 10 candy bars is 10 percent less than the charge for purchasing the 10 candy bars individually. Given: $$x=0.9*10y$$. Two unknowns one equation. Not sufficient to calculate $$x$$.

(1)+(2) We have two distinct linear equations with two unknowns so we can solve for $$x$$ and $$y$$. Sufficient.

_________________
Intern
Joined: 01 Apr 2016
Posts: 2

### Show Tags

04 Sep 2017, 01:18
Hi there

Just wondering if the first stmt could be true by itself?

From the facts we understand that one pack of 10 is cheaper than 10 individual bars. I.e. X < 10Y

From first statement we have that X-8Y=2

If X is less than 10Y but must be greater than 8Y, could we say that it should be 9Y here. Or am I am I just assuming that it should be an integer..
Math Expert
Joined: 02 Sep 2009
Posts: 47981

### Show Tags

04 Sep 2017, 01:32
warmpied wrote:
Hi there

Just wondering if the first stmt could be true by itself?

From the facts we understand that one pack of 10 is cheaper than 10 individual bars. I.e. X < 10Y

From first statement we have that X-8Y=2

If X is less than 10Y but must be greater than 8Y, could we say that it should be 9Y here. Or am I am I just assuming that it should be an integer..

Yes, we are not told that x and y must be integers.
_________________
Manager
Joined: 22 May 2017
Posts: 92
GMAT 1: 580 Q41 V29
GMAT 2: 580 Q43 V27

### Show Tags

20 Dec 2017, 20:07
Bunuel wrote:
warmpied wrote:
Hi there

Just wondering if the first stmt could be true by itself?

From the facts we understand that one pack of 10 is cheaper than 10 individual bars. I.e. X < 10Y

From first statement we have that X-8Y=2

If X is less than 10Y but must be greater than 8Y, could we say that it should be 9Y here. Or am I am I just assuming that it should be an integer..

Yes, we are not told that x and y must be integers.

Bunuel technically, how a candy bar can be integer.
I think answer should be A.
Math Expert
Joined: 02 Sep 2009
Posts: 47981

### Show Tags

20 Dec 2017, 20:25
Bunuel wrote:
warmpied wrote:
Hi there

Just wondering if the first stmt could be true by itself?

From the facts we understand that one pack of 10 is cheaper than 10 individual bars. I.e. X < 10Y

From first statement we have that X-8Y=2

If X is less than 10Y but must be greater than 8Y, could we say that it should be 9Y here. Or am I am I just assuming that it should be an integer..

Yes, we are not told that x and y must be integers.

Bunuel technically, how a candy bar can be integer.
I think answer should be A.

x = 8y + 2. Consider two cases:

x = 18 and y = 2 (notice x < 10y is satisfied);
x = 26 and y = 3 (notice x < 10y is satisfied).
_________________
Intern
Joined: 11 Jan 2016
Posts: 6

### Show Tags

02 Aug 2018, 14:57
Bunuel Hi,

I statement -: If is 8 candy is X then 10Pack is X+2 .. Not suffi
II Statement -:if 10 candy individually X then 10 Pack would be 9/10X ... NO suffie

Combine -: 8/X* 10 *9/10 = X+2 ..Give X^2 +2x - 72 , so shouldn't the ans be E
Math Expert
Joined: 02 Sep 2009
Posts: 47981

### Show Tags

02 Aug 2018, 21:02
sunnyattri wrote:
Bunuel Hi,

I statement -: If is 8 candy is X then 10Pack is X+2 .. Not suffi
II Statement -:if 10 candy individually X then 10 Pack would be 9/10X ... NO suffie

Combine -: 8/X* 10 *9/10 = X+2 ..Give X^2 +2x - 72 , so shouldn't the ans be E

Let me ask you: what is the price for purchasing the candy bar individually in your equations? Is it x/8 or x/10? And could it be both? It's not clear what you've written there. It's better to denote by a variable the price for purchasing the candy bar individually.
_________________
Intern
Joined: 11 Jan 2016
Posts: 6

### Show Tags

02 Aug 2018, 23:14
@bunuel

let me ask you: what is the price for purchasing the candy bar individually in your equations? Is it x/8 or x/10? And could it be both? It's not clear what you've written there. It's better to denote by a variable the price for purchasing the candy bar individually.[/quote]

It's X/8 for one individual candy bar,so multiply by 10 to get the price for 10 Individual candy bar then i took 90% of that which in turn equal to X+2
Math Expert
Joined: 02 Sep 2009
Posts: 47981

### Show Tags

02 Aug 2018, 23:22
sunnyattri wrote:

It's X/8 for one individual candy bar,so multiply by 10 to get the price for 10 Individual candy bar then i took 90% of that which in turn equal to X+2

Then it should be x + 2 = (x/8*10)*0.9, which gives x = 16.
_________________
Intern
Joined: 11 Jan 2016
Posts: 6

### Show Tags

02 Aug 2018, 23:28
sunnyattri wrote:

It's X/8 for one individual candy bar,so multiply by 10 to get the price for 10 Individual candy bar then i took 90% of that which in turn equal to X+2

Then it should be x + 2 = (x/8*10)*0.9, which gives x = 16.

Bunuel ya it should be! i don't know what calculation i did back there .. sorry for trouble and thanks.

But the approach is right?
Math Expert
Joined: 02 Sep 2009
Posts: 47981

### Show Tags

02 Aug 2018, 23:30
sunnyattri wrote:
sunnyattri wrote:

It's X/8 for one individual candy bar,so multiply by 10 to get the price for 10 Individual candy bar then i took 90% of that which in turn equal to X+2

Then it should be x + 2 = (x/8*10)*0.9, which gives x = 16.

Bunuel ya it should be! i don't know what calculation i did back there .. sorry for trouble and thanks.

But the approach is right?

Yes, x + 2 = (x/8*10)*0.9 is correct.
_________________
Re: M19-25 &nbs [#permalink] 02 Aug 2018, 23:30
Display posts from previous: Sort by

# M19-25

Moderators: chetan2u, Bunuel

# Events & Promotions

 Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.