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

 It is currently 23 Oct 2018, 07:03

### 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

# Over a certain time period, did the number of shares of

Author Message
TAGS:

### Hide Tags

Intern
Joined: 22 Mar 2010
Posts: 46
Over a certain time period, did the number of shares of  [#permalink]

### Show Tags

17 Jul 2010, 11:23
2
12
00:00

Difficulty:

55% (hard)

Question Stats:

60% (01:37) correct 40% (01:21) wrong based on 407 sessions

### HideShow timer Statistics

Over a certain time period, did the number of shares of stock in Ruth's portfolio increase?

(1) Over the time period, the ratio of number of shares of stock to the total number of shares of stocks and bonds in Ruth's portfolio increased.
(2) Over the time period, the total number of shares of stocks and bonds in Ruth's portfolio increased.
Math Expert
Joined: 02 Sep 2009
Posts: 50058
Over a certain time period, did the number of shares of  [#permalink]

### Show Tags

17 Jul 2010, 11:59
8
3
Over a certain time period, did the number of shares of stock in Ruth's portfolio increase?

Let the # of stock be $$s$$ and the # of bonds be $$b$$. The question is did $$s$$ increase?

(1) Over the time period, the ratio of number of shares of stock to the total number of shares of stocks and bonds in Ruth's portfolio increased. $$\frac{s}{s+b}$$ increased. Not sufficient, as for example it's possible that $$s$$ increased $$b$$ remained the same or $$s$$ remained the same and $$b$$ decreased.

(2) Over the time period, the total number of shares of stocks and bonds in Ruth's portfolio increased. $$s+b$$ increased. Clearly insufficient.

(1)+(2) $$\frac{s}{s+b}$$ increased and $$s+b$$ (denominator) also increased, so it must be true that $$s$$ (nominator) increased too. Sufficient.

Hope it's clear.
_________________
##### General Discussion
Intern
Joined: 22 Mar 2010
Posts: 46

### Show Tags

17 Jul 2010, 11:27
1
I chose A...but it isnt the correct answer.
Logic :
(#of shares of stocks/Tot shares+bonds)-->increases
Hence number of shares of stocks would have a direct dependency, hence it increase as well.
Director
Joined: 26 Oct 2016
Posts: 641
Location: United States
Schools: HBS '19
GMAT 1: 770 Q51 V44
GPA: 4
WE: Education (Education)
Re: Over a certain time period, did the number of shares of  [#permalink]

### Show Tags

08 Feb 2017, 20:36
2
1) The ratio of shares:total could increase by adding more shares or by reducing the number of bonds. Insufficient.

2) The total number could increase by adding shares, adding bonds, or both. Insufficient.

Combined, we know the total number of shares and bonds went up, and we know the ratio of shares:total went up. The only way both statements can be true is if the number of shares increased. Thus, we need both statements.
Hence C.
_________________

Thanks & Regards,
Anaira Mitch

Intern
Joined: 20 Jan 2018
Posts: 18
GMAT 1: 620 Q50 V24
Re: Over a certain time period, did the number of shares of  [#permalink]

### Show Tags

29 Mar 2018, 00:44
EnterMatrix wrote:
I chose A...but it isnt the correct answer.
Logic :
(#of shares of stocks/Tot shares+bonds)-->increases
Hence number of shares of stocks would have a direct dependency, hence it increase as well.

Even I did the question with the same logic, since the ratio is increasing so either only numerator increases or both numr and denomr should be increasing.
Re: Over a certain time period, did the number of shares of &nbs [#permalink] 29 Mar 2018, 00:44
Display posts from previous: Sort by