GMAT Data Sufficiency Discussions

MBA GMAT
689
3. Ans C
Consider there are 100 projects so as per question

25 of the projects have 4 or more employees
35 of the projects have 2 or fewer employees

so rest ie 40 projects have 3 employees each
So the median no: of employees wiil be 3.

ashishjha,

how could u conclude that it is C?
i didn't understand how the median has to be 3.
pls explain....
690
ashishjha,

how could u conclude that it is C?
i didn't understand how the median has to be 3.
pls explain....

3. Ans C
Consider there are 100 projects so as per question

25 of the projects have 4 or more employees
35 of the projects have 2 or fewer employees

so rest ie 40 projects have 3 employees each
So the median no: of employees wiil be 3.


a) 25 projects have members with 4 or more (They will form the later part of the series)
b) 35 projects have members with 2 or less (They will form the earlier part of the series)
c) Rest 40 projects have exactly 3 members (They will be from the 36th to 75th number of the series)

So the median (50th and 51th number) will be = (3+3)/2 = 3

If the number of projects are odd in number, the median will be simply 3.

Hope this helps.........:-o
691
a) 25 projects have members with 4 or more (They will form the later part of the series)
b) 35 projects have members with 2 or less (They will form the earlier part of the series)
c) Rest 40 projects have exactly 3 members (They will be from the 36th to 75th number of the series)

So the median (50th and 51th number) will be = (3+3)/2 = 3

If the number of projects are odd in number, the median will be simply 3.

Hope this helps.........:-o


Nothing is mentioned about the no.of member os rest 40% projects. Can you please tell me how did you deduce this?
692
alchemist-mba Says
Nothing is mentioned about the no.of member os rest 40% projects. Can you please tell me how did you deduce this?

It can be calculated from both statements....... 25% of projects have memebers >4 and 35% of projects have memebers
If u plot this on a number line only integer value, 2
Pls let me know whether u understood my reasoning........
693
It can be calculated from both statements....... 25% of projects have memebers >4 and 35% of projects have memebers
If u plot this on a number line only integer value, 2
Pls let me know whether u understood my reasoning........


sorry - But I still could not follow you.
How did you set the limit on a.
25% of projects have memebers >4 and 35% of projects have memebers 4 or
694
sorry - But I still could not follow you.
How did you set the limit on a.
25% of projects have memebers >4 and 35% of projects have memebers 4 or

By looking at the question statement, one would know that 25% of projects would have 4 or more (It takes care of all the numbers with and beyond 4)

35% of projects have 2 or less employees(ie projects with 1 & 2 members).

Left are 40% of projects which has exactly 3 employees per project. :idea:
695
By looking at the question statement, one would know that 25% of projects would have 4 or more (It takes care of all the numbers with and beyond 4)

35% of projects have 2 or less employees(ie projects with 1 & 2 members).

Left are 40% of projects which has exactly 3 employees per project. :idea:


Yep.. Thanks.. wht amI doing.. its too early in the morning for me and with long weekend ahead..i guess imnt thinking :-).... once agian thanks for kicking me off my slumber..
696

During an experiment, some water was removed from each of 6 water tanks. If the standard deviation of the volumes of water in the tanks at the beginning of the experiment was 10 gallons, what was the standard deviation of the volumes of water in the tanks at the end of the experiment?

1) For each tank, 30 percent of the volume of water that was in the tank at the beginning of the experiment was removed during the experiment.

2) The average (arithmetic mean) volume of water in the tanks at the end of the experiment was 63 gallons.
-----------------------------------------------------------------------

Is m + z > 0?

1) m-3z > 0

2) 4z-m > 0

----------------------------------------------------------------------
If the integers a & n are greater than 1 and the product of the first 8 positive integers is a multiple of a^n (a raised to the power n), what is the value of a?

1) a^n = 64

2) n = 6

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697

Is m + z > 0?

1) m-3z > 0

2) 4z-m > 0


I think E.....

1. m>3z
when z=1 m=4 m+z>0
when z=-2 m=-1 m+z
2. 4z>m
when z=1 m=2 m+z>0
when z=-1 m=-5 m+z
1 & 2 --->
3z
z=2 m=7 m+z>0
z=-2 m=-7 m+z
So E

Pls correct me if i'm wrong......

698

I chose (E) as well.. but the OA is (C). This question is from GMAT prep. Can someone plz help?!

Is m + z > 0?

1) m-3z > 0

2) 4z-m > 0


I think E.....

1. m>3z
when z=1 m=4 m+z>0
when z=-2 m=-1 m+z
2. 4z>m
when z=1 m=2 m+z>0
when z=-1 m=-5 m+z
1 & 2 --->
3z
z=2 m=7 m+z>0
z=-2 m=-7 m+z
So E

Pls correct me if i'm wrong......
699
*arch* Says
I chose (E) as well.. but the OA is (C). This question is from GMAT prep. Can someone plz help?!



Nice Question..

First Equation => m > 3z => Insufficent
Second Equation => m Insufficent

Combining both, we have 3z => 3z z must be postive for this to happen.

Now since z > 0, 3z >0 and hence m > 0.. And therefore m + z > 0. and 'C' is the answer.

Hope this helps
700
A parent established a college fund for his daughter. Each year the parent made a
contribution to the fund, and each year he increased his contribution by a constant
amount. If he made a contribution of $800 in the first year, by what amount did the
parent increase his contribution to the fund each year?
(1) The parents contribution to the fund in the 18th year was $7600.
(2) The parents contribution to the fund in the 7th year was twice what it was in
the 3rd year.

Does the decimal equivalent of P/Q, where P and Q are positive integers, contain only
a finite number of nonzero digits?
(1) P>Q
(2) Q=8

From May 1 to May 30 in the same year, the balance in a checking account increased.
What was the balance in the checking account on May 30?
(1) If, during this period of time, the increase in the balance in the checking
account had been 12 percent, then the balance in the account on May 30 would
have been $504
(2) During this period of time, the increase in the balance in the checking account
was 8 percent.
701
A parent established a college fund for his daughter. Each year the parent made a
contribution to the fund, and each year he increased his contribution by a constant
amount. If he made a contribution of $800 in the first year, by what amount did the
parent increase his contribution to the fund each year?
(1) The parents contribution to the fund in the 18th year was $7600.
(2) The parents contribution to the fund in the 7th year was twice what it was in
the 3rd year.

Does the decimal equivalent of P/Q, where P and Q are positive integers, contain only
a finite number of nonzero digits?
(1) P>Q
(2) Q=8

From May 1 to May 30 in the same year, the balance in a checking account increased.
What was the balance in the checking account on May 30?
(1) If, during this period of time, the increase in the balance in the checking
account had been 12 percent, then the balance in the account on May 30 would
have been $504
(2) During this period of time, the increase in the balance in the checking account
was 8 percent.


Are ans D,B,C.....?
702
A parent established a college fund for his daughter. Each year the parent made a

contribution to the fund, and each year he increased his contribution by a constant
amount. If he made a contribution of $800 in the first year, by what amount did the
parent increase his contribution to the fund each year?
(1) The parents contribution to the fund in the 18th year was $7600.
(2) The parents contribution to the fund in the 7th year was twice what it was in
the 3rd year.

Does the decimal equivalent of P/Q, where P and Q are positive integers, contain only
a finite number of nonzero digits?
(1) P>Q
(2) Q=8

From May 1 to May 30 in the same year, the balance in a checking account increased.
What was the balance in the checking account on May 30?
(1) If, during this period of time, the increase in the balance in the checking
account had been 12 percent, then the balance in the account on May 30 would
have been $504
(2) During this period of time, the increase in the balance in the checking account
was 8 percent.



My take would be : D, E & A
703
ashishjha100 Says
Are ans D,B,C.....?


OA's are D, E, A

Can u explain how u solved the first question? Thanks.
704
alchemist-mba Says
My take would be : D, E & A


Yeah OA's are D, E, A.

Please explain how. Thanks
705
Hey guys, help me out in this one as well. The question is very easy but I am confused :-)

The operation* represents either addition, subtraction, or multiplication of integers,
what is the value of 1*0?
(1) 0*2=2
(2) 2*0=2

My answer was D but OA is A.

1) only addition satisfies the equation 0+2 = 2; so we know what will be the value of 1*0; Sufficient
2) It can be addition or subtraction, however in both the cases we will still know the value of 1*0. Just like 2-0=2 or 2+0=2, 1-0=1 or 1+0=1; So sufficient.

According to me, the question is not asking about the sign rather asking the value of 1*0 which can be answered by both options.

So your precious comments are needed. Thanks.
706
Yeah OA's are D, E, A.

Please explain how. Thanks


1. The Contribution must be in the lines of 800 + a * n
a -> The Constant Term
n -> Year.
Stmt 1. The parents contribution to the fund in the 18th year was $7600. => 800 + a * 17 = 7600... => Sufficient

Stmt 2. The parents contribution to the fund in the 7th year was twice what it was in the 3rd year.
=> (800 + a * 6) = 2 * (800 + a * 2) => Sufficient

2. P and Q are positive integers and only when we know them can we talk about P/Q.
Stmt 1 => P > Q => depending on individual values the value P/Q Varies => Not Sufficient
Stmt 2 => Q = 8. depending on values of P P/8 Varies => Not Sufficient

Combingin both also doesnt yield a value of P.. hence both are not sufficient.

3.

Stmt 1 -> a + (a * 12/100) = 504 .. so a can be solved => Suffiecient.
Stmt 2 -> Rate is given but we dont know principle...so.. we cannot find the balance..

Hope this helps
707
Hey guys, help me out in this one as well. The question is very easy but I am confused :-)


The operation* represents either addition, subtraction, or multiplication of integers,
what is the value of 1*0?
(1) 0*2=2
(2) 2*0=2
My answer was D but OA is A.
1) only addition satisfies the equation 0+2 = 2; so we know what will be the value of 1*0; Sufficient
2) It can be addition or subtraction, however in both the cases we will still know the value of 1*0. Just like 2-0=2 or 2+0=2, 1-0=1 or 1+0=1; So sufficient.
According to me, the question is not asking about the sign rather asking the value of 1*0 which can be answered by both options.
So your precious comments are needed. Thanks.


Hmm. since it is asked abt the value 1 * 0.. i would agree with you.. my answer is D too..
708
A parent established a college fund for his daughter. Each year the parent made a contribution to the fund, and each year he increased his contribution by a constant amount. If he made a contribution of $800 in the first year, by what amount did the

parent increase his contribution to the fund each year?
(1) The parent's contribution to the fund in the 18th year was $7600.
(2) The parent's contribution to the fund in the 7th year was twice what it was in the 3rd year.


Does the decimal equivalent of P/Q, where P and Q are positive integers, contain only a finite number of nonzero digits?
(1) P>Q
(2) Q=8

From May 1 to May 30 in the same year, the balance in a checking account increased.
What was the balance in the checking account on May 30?
(1) If, during this period of time, the increase in the balance in the checking account had been 12 percent, then the balance in the account on May 30 would have been $504
(2) During this period of time, the increase in the balance in the checking account was 8 percent.


1. The Contribution must be in the lines of 800 + a * n
a -> The Constant Term
n -> Year.
Stmt 1. The parent's contribution to the fund in the 18th year was $7600. => 800 + a * 17 = 7600... => Sufficient

Stmt 2. The parent's contribution to the fund in the 7th year was twice what it was in the 3rd year.
=> (800 + a * 6) = 2 * (800 + a * 2) => Sufficient

2. P and Q are positive integers and only when we know them can we talk about P/Q.
Stmt 1 => P > Q => depending on individual values the value P/Q Varies => Not Sufficient
Stmt 2 => Q = 8. depending on values of P P/8 Varies => Not Sufficient

Combingin both also doesnt yield a value of P.. hence both are not sufficient.

3.

Stmt 1 -> a + (a * 12/100) = 504 .. so a can be solved => Suffiecient.
Stmt 2 -> Rate is given but we dont know principle...so.. we cannot find the balance..

Hope this helps


Alchemist,
I have some doubts in ur reasoning for 2nd & 3rd questions.......

2.The question is asking for no specific value of P/Q .It is asking "
Does the decimal equivalent of P/Q, where P and Q are positive integers, contain only
a finite number of nonzero digits?"

ie is P/Q is a terminating decimal......
If a fraction P/Q with Q having 2 or 5 as its prime factors, regardless of the value of P, the fraction will terminate......u can use values to check this
In B it is said that Q=8=2^3 so it has finite value....... So i think B

3.The question is asking for the amount in 30th May and not 1st May........
I think ur variable 'a' denotes the amount in 1st may.......then without 2nd statement hw can u calculate amount in 30th may.......so i think C

Simmy,
Pls check for OA of 2nd question.......it will be B.....wats the source of these questions.?is it areliable one?

Pls correct me if i'm wrong