Author 
Message 
TAGS:

Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 60480

Robin invested a total of $12,000 in two investments, X and Y, so that
[#permalink]
Show Tags
22 Jun 2018, 01:55
Question Stats:
73% (01:22) correct 27% (01:23) wrong based on 1156 sessions
HideShow timer Statistics
Robin invested a total of $12,000 in two investments, X and Y, so that the investments earned the same amount of simple annual interest. How many dollars did Robin invest in investment Y ? (1) Investment X paid 3 percent simple annual interest, and investment Y paid 6 percent simple annual interest. (2) Robin invested more than $1,000 in investment X. NEW question from GMAT® Official Guide 2019 (DS02441)
Official Answer and Stats are available only to registered users. Register/ Login.
_________________




Math Expert
Joined: 02 Aug 2009
Posts: 8341

Re: Robin invested a total of $12,000 in two investments, X and Y, so that
[#permalink]
Show Tags
22 Jun 2018, 03:25
Bunuel wrote: Robin invested a total of $12,000 in two investments, X and Y, so that the investments earned the same amount of simple annual interest. How many dollars did Robin invest in investment Y ? (1) Investment X paid 3 percent simple annual interest, and investment Y paid 6 percent simple annual interest. (2) Robin invested more than $1,000 in investment X. NEW question from GMAT® Official Guide 2019 (DS02441) Simple interest = PRT/100, where P is principal, R rate of interest and T is time.. Here time is 1 year, as we are looking at simple annual interest.. SAI=PR/100.. 1) statement I gives the two rate of interest as 3 and 6.. So z*3/100=(12000z)*6/100.. It's a linear equation in z, you can find the value of z Sufficient 2) statement II tells us that Robin invested $1000 more.. Nothing much Insufficient A
_________________




Manager
Joined: 10 Jun 2018
Posts: 51
Location: Australia
Concentration: Technology, General Management
GPA: 2.88
WE: Science (Pharmaceuticals and Biotech)

Re: Robin invested a total of $12,000 in two investments, X and Y, so that
[#permalink]
Show Tags
22 Jun 2018, 03:27
Statement 1: If investment Y paid double the interest of investment X, then investment X must be double that of investment Y to get the same amount of interest earnt. Therefore, the ratio of X:Y is 2:1, and so investment X is $8000, investment Y is $4000. Statement 2 ain’t got enough info. So answer is A.Posted from my mobile device
_________________
Not a professional entity or a quant/verbal expert or anything. So take my answers with a grain of salt.




eGMAT Representative
Joined: 04 Jan 2015
Posts: 3209

Re: Robin invested a total of $12,000 in two investments, X and Y, so that
[#permalink]
Show Tags
22 Jun 2018, 03:47
Solution Given:• Robin invested total $12000 in two investments, X and Y • The investments earned same amount of simple annual interest To find:• The amount (dollars) Robin invested in Y Analysing Statement 1• As per the information given in statement 1, investment X paid 3% simple interest whereas investment Y paid 6% simple interest • If we assume that investment in X is P, then investment in Y will be (12000 – P) • As the simple annual interest earned is same, we can write:
o \(\frac{P * 3}{100} = \frac{(12000 – P) * 6}{100}\) • We can get the value of P as well as (12000 – P) Hence, statement 1 is sufficient to answer Analysing Statement 2• As per the information given in statement 2, Robin invested more than $1000 in investment X
o From this, we cannot find out the exact investment in X and Y individually Hence, statement 2 is not sufficient to answer Hence, the correct answer is option A. Answer: A
_________________



GMAT Club Legend
Joined: 12 Sep 2015
Posts: 4214
Location: Canada

Re: Robin invested a total of $12,000 in two investments, X and Y, so that
[#permalink]
Show Tags
23 Jun 2018, 07:35
Bunuel wrote: Robin invested a total of $12,000 in two investments, X and Y, so that the investments earned the same amount of simple annual interest. How many dollars did Robin invest in investment Y ?
(1) Investment X paid 3 percent simple annual interest, and investment Y paid 6 percent simple annual interest. (2) Robin invested more than $1,000 in investment X.
Let X = The number of dollars invested in investment X Let Y = The number of dollars invested in investment YTarget question: What is the value of Y? Given: Robin invested a total of $12,000 in two investments, X and Y, so that the investments earned the same amount of simple annual interest. If the total investment is $12,000, we can write: X + Y = 12,000 Statement 1: Investment X paid 3 percent simple annual interest, and investment Y paid 6 percent simple annual interest. So, the annual interest paid by investment X = 0.03X and the interest paid by investment Y = 0.06Y Since the annual interest on the two investments are EQUAL, we can write: 0.03X = 0.06Y We now have the following system of linear equations: X + Y = 12,0000.03X = 0.06Y Since we COULD solve this system for Y, we COULD answer the target question with certainty (but we would never waste valuable time actually solving the system!) Since we could answer the target question with certainty, statement 1 is SUFFICIENT Statement 2: Robin invested more than $1,000 in investment X.Since we don't know the exact value of the amount Robin invested in X, and since we don't know anything about the interest rates for the investments, we cannot answer the target question with certainty. So, statement 2 is NOT SUFFICIENT ASIDE: If you're not convinced that statement 2 is not sufficient, consider these two cases: Case a: X = 6,000, Y = 6,000, and the interest rate for each investment is 10%. Notice that the interest for each investment will be equal. Here, the answer to the target question is Y = 6,000Case b: X = 2000, Y = 10,000, the interest rate for investment X is 50%, and the interest rate for investment Y is 10%. Notice that the interest for each investment will be equal. Here, the answer to the target question is Y = 10,000Since we cannot answer the target question with certainty, statement 2 is NOT SUFFICIENT Answer: A Cheers, Brent
_________________
Test confidently with gmatprepnow.com



Manager
Joined: 07 May 2015
Posts: 62
Location: India
GPA: 4

Re: Robin invested a total of $12,000 in two investments, X and Y, so that
[#permalink]
Show Tags
16 Sep 2018, 10:33
Bunuel wrote: Robin invested a total of $12,000 in two investments, X and Y, so that the investments earned the same amount of simple annual interest. How many dollars did Robin invest in investment Y ? (1) Investment X paid 3 percent simple annual interest, and investment Y paid 6 percent simple annual interest. (2) Robin invested more than $1,000 in investment X. NEW question from GMAT® Official Guide 2019 (DS02441) (a) X+Y = 12000 0.03X = 0.06Y X = 2Y Hence solvable, Suffficient
(b) X>1000 > Not sufficient



Intern
Joined: 10 Feb 2018
Posts: 2

Re: Robin invested a total of $12,000 in two investments, X and Y, so that
[#permalink]
Show Tags
01 Jan 2019, 04:56
How are we able to infer that thetime period of investments are same ?



Intern
Joined: 28 Mar 2019
Posts: 7

Re: Robin invested a total of $12,000 in two investments, X and Y, so that
[#permalink]
Show Tags
24 Jul 2019, 03:09
Simararora94 wrote: How are we able to infer that thetime period of investments are same ? I was just wondering the same. Got it right because of the simple interest, thought they assumed it. But it's not very clear. Can someone clarify the reason the time is assumed to be one year? thanks



VP
Joined: 18 Dec 2017
Posts: 1001
Location: United States (KS)
GMAT 1: 600 Q46 V27

Re: Robin invested a total of $12,000 in two investments, X and Y, so that
[#permalink]
Show Tags
26 Jul 2019, 12:05
Azedenkae wrote: Statement 1: If investment Y paid double the interest of investment X, then investment X must be double that of investment Y to get the same amount of interest earnt.
Therefore, the ratio of X:Y is 2:1, and so investment X is $8000, investment Y is $4000.
Statement 2 ain’t got enough info. :P
So answer is A.
Posted from my mobile device Yup I followed the same approach. Since 3 and 6 percent have to result in same interest the principals are probably in 2:1 leading to 8000 and 4000 and you can find out. B doesn't help on it's own and does nothing to support A either. Hence A
_________________
The Moment You Think About Giving Up, Think Of The Reason Why You Held On So Long Learn from the Legend himself: All GMAT Ninja LIVE YouTube videos by topicYou are missing on great learning if you don't know what this is: Project SC Butler



Manager
Joined: 12 Mar 2017
Posts: 204
Location: India
Concentration: Strategy, General Management
GPA: 4

Re: Robin invested a total of $12,000 in two investments, X and Y, so that
[#permalink]
Show Tags
02 Sep 2019, 11:37
chetan2u wrote: Bunuel wrote: Robin invested a total of $12,000 in two investments, X and Y, so that the investments earned the same amount of simple annual interest. How many dollars did Robin invest in investment Y ? (1) Investment X paid 3 percent simple annual interest, and investment Y paid 6 percent simple annual interest. (2) Robin invested more than $1,000 in investment X. NEW question from GMAT® Official Guide 2019 (DS02441) Simple interest = PRT/100, where P is principal, R rate of interest and T is time.. Here time is 1 year, as we are looking at simple annual interest.. SAI=PR/100.. 1) statement I gives the two rate of interest as 3 and 6.. So z*3/100=(12000z)*6/100.. It's a linear equation in z, you can find the value of z Sufficient 2) statement II tells us that Robin invested $1000 more.. Nothing much Insufficient A chetan2uHow can we infer that the time for both investments was the same. It could’ve been different. In that case E would be the answer



Intern
Joined: 12 Dec 2012
Posts: 15
Location: United States (GA)
GPA: 4

Re: Robin invested a total of $12,000 in two investments, X and Y, so that
[#permalink]
Show Tags
20 Sep 2019, 06:01
For many folks(including me), who are wondering where is the time period specified, focus on the language of the question. That is the trick in this otherwise simple question.
"Robin invested a total of $12,000 in two investments, X and Y, so that the investments earned the same amount of simple annual interest. How many dollars did Robin invest in investment Y ?"
"simple annual interest" and not "simple interest" so, the time period is 1 year.



Intern
Joined: 27 May 2018
Posts: 14

Re: Robin invested a total of $12,000 in two investments, X and Y, so that
[#permalink]
Show Tags
25 Dec 2019, 23:23
Bunuel wrote: Robin invested a total of $12,000 in two investments, X and Y, so that the investments earned the same amount of simple annual interest. How many dollars did Robin invest in investment Y ? (1) Investment X paid 3 percent simple annual interest, and investment Y paid 6 percent simple annual interest. (2) Robin invested more than $1,000 in investment X. NEW question from GMAT® Official Guide 2019 (DS02441) Ans A Simple weighted Average problem. Interest ratio 3:6 i.e. 1:2 For interest earned to be same, X: Y must be opposite of Interest ratio i.e. 2:1.( 8000:4000) 8000x3=4000x6
_________________
GMAT Side effects  GGroggy MMental AAnnoyed TTwitted




Re: Robin invested a total of $12,000 in two investments, X and Y, so that
[#permalink]
25 Dec 2019, 23:23






