GMAT Data Sufficiency Discussions

MBA GMAT
481
Hi Vicky,

Can u pls explain in detail..b) option..arriving at 1 or 2..

2. a) y can be any positive integer
b) y can be either 1 or 2
Combining a and b...y=2...ans...C

Cheers.

If x and x+2 are both multiples of the same number...that can only happen if that number is 1 or 2 ... ex. x=4 x+2=6 ... multiples of 1 and 2 ... ex. x=3 and x+2=5 ... only common multiple is 1... so we will get either 1 or 2 as y...

hope this helps...
482
1.What is the rate, in cubic feet per minute, at which water is flowing into a certain rectangular tank?
(1) The height of the water in the tank is increasing at the rate of 2 feet per minute.
(2) The capacity of the tank is 216 cubic feet.
OA E
2. If x and y are positive integers and x is a multiple of y, is y = 2?
(1) y 1
(2) x + 2 is a multiple of y.
OA C

3.Pam and Ed are in a line to purchase tickets. How many people are in the line?
(1) There are 20 people behind Pam and 20 people in front of Ed.
(2) There are 5 people between Pam and Ed.
OA
pls help with reasoning.......

1. None of the statement is talking ne thing abt the time, which is indispensable for determining for rate. so answer is E.

2. x = ky, k is +ve
from 1, cannot say ne thing.
from 2, (x+2) = my, m is +ve. so cannot say ne thing.
from 1 and 2, 2 =2*1=1*2= y*(m-k), but y != 1, so y = 2. Hence E.

3.
from 1: 20 P*E 20 or E19P, so cannot say.
from 2: *E5P* or *P5E*, so cannot say ne thing. here * can be ne number.
from 1 and 2: 20P5E20 and 14E5P14 both satisfy the given conditions at a time. so cannot Say ne thing.
Hence the answer is E.
483

Pls help........

484
ashishjha100 Says
Pls help........

 1. If denotes a mathematical operation, does
xy=yx for all x and y?
(1) For all x and y, xy = 2(x2 + y2).
(2) For all y, 0y = 2 y2
the question is, can u replace x with y in the given operation.
1 => if you replace x with y..it is gives the same result..so YES
2 => there is no information regarding x..so no.
So I think ans is A


2. What is the value of x|?
(1) x = -|x
(2) x2 = 4
1=> this does not give any information about value.
2=> x can be 2 or -2. But mod x is 2.. and we dont need (1) to come to conclusion.
So I think ans is B


3.By what percent was the price of a certain candy bar increased?
(1) The price of the candy bar was increased by 5 cents.
(2) The price of the candy bar after the increase was 45 cents.
To answer the question, we need atleast two of these three: price before, price after, increased amount.
1=> only gives amount increased. So cannot answer alone
2=> give price after..cannot answer alone.
So we can answer using both 1 & 2. So ans is D
4. Are the numbers k/4, z/3 and r/2 in increasing order?
(1) 3 z
(2) r z k
1=> z is between 3 and 4. So 133. k and r can be +,- or zero. So we cant answer either yes or no to the question.
2=> z is between r and k..but either k or r can be +,- or zero. So we cant answer either yes or no to the question.
If u combine both..z is between 3 and 4 and between r and k..
r can be anything less or equal to 3. So r/2 =
z can be 13span>
k can be greater than or equal to 4. So k/4 => 1
So we can have 1, 1.2, 1.5 OR 10, 1.2, 1
{the values or r and k can be other than those stated above. Because if z is 3.5 r can be 3.4 and k can be 3.6}
So answer is E.


5. If x 1, is y equal to x + 1?
(1) (y-2)/(x-1) = 1
(2) y2 = (x + 1)2
1=> if u replace y with x+1, the equation is satisfied
2=> same again.
So ans is D.
485

1. If denotes a mathematical operation, does
xy=yx for all x and y?
(1) For all x and y, xy = 2(x2 + y2).
(2) For all y, 0y = 2 y2
the question is, can u replace x with y in the given operation.
1 => if you replace x with y..it is gives the same result..so YES
2 => there is no information regarding x..so no.
So I think ans is A


2. What is the value of x|?
(1) x = -|x
(2) x2 = 4
1=> this does not give any information about value.
2=> x can be 2 or -2. But mod x is 2.. and we dont need (1) to come to conclusion.
So I think ans is B


3.By what percent was the price of a certain candy bar increased?
(1) The price of the candy bar was increased by 5 cents.
(2) The price of the candy bar after the increase was 45 cents.
To answer the question, we need atleast two of these three: price before, price after, increased amount.
1=> only gives amount increased. So cannot answer alone
2=> give price after..cannot answer alone.
So we can answer using both 1 & 2. So ans is D
4. Are the numbers k/4, z/3 and r/2 in increasing order?
(1) 3 z
(2) r z k
1=> z is between 3 and 4. So 133. k and r can be +,- or zero. So we cant answer either yes or no to the question.
2=> z is between r and k..but either k or r can be +,- or zero. So we cant answer either yes or no to the question.
If u combine both..z is between 3 and 4 and between r and k..
r can be anything less or equal to 3. So r/2 =
z can be 13span>
k can be greater than or equal to 4. So k/4 => 1
So we can have 1, 1.2, 1.5 OR 10, 1.2, 1
{the values or r and k can be other than those stated above. Because if z is 3.5 r can be 3.4 and k can be 3.6}
So answer is E.


5. If x 1, is y equal to x + 1?
(1) (y-2)/(x-1) = 1
(2) y2 = (x + 1)2
1=> if u replace y with x+1, the equation is satisfied
2=> same again.
So ans is D.


last Q
5. If x 1, is y equal to x + 1?
(1) (y-2)/(x-1) = 1
(2) y^2 = (x + 1)^2
OA is A
486
last Q
5. If x 1, is y equal to x + 1?
(1) (y-2)/(x-1) = 1
(2) y^2 = (x + 1)^2
OA is A


my bad.. y can be -(x+1) for the second statement.

wat is OA??
487
my bad.. y can be -(x+1) for the second statement.

wat is OA??

Ans given is A
488

Hi.. can someone plz help me with this question?

If a, b, and c are integers, is a-b+c > a+b-c ?

1) b is positive
2) c is negative

When you have a question that asks you whether one quantity is greater than the other with a common quantity present - for eg a+b > a+c (given b>c) do you need to know if a is +ve or -ve?

489
Hi.. can someone plz help me with this question?

If a, b, and c are integers, is a-b+c > a+b-c ?

1) b is positive
2) c is negative

When you have a question that asks you whether one quantity is greater than the other with a common quantity present - for eg a+b > a+c (given b>c) do you need to know if a is +ve or -ve?

Here i think ans is C

eq bols down to c-b>b-c
1) b is positive
without c cant say anything....
2) c is negative
without b cant say anything....

Taking together c-b will always negative and b-c always positive.....so we will get result.....

When you have a question that asks you whether one quantity is greater than the other with a common quantity present - for eg a+b > a+c (given b>c) do you need to know if a is +ve or -ve?

u dont need to know as shown in eg above......
490
ABCD is a rectangle, E is a point somewhere on side BC.
Is the area of triangle ABE > 25 ?

(1) AB = 6

(2) AE = 10

(A) Statement (1) alone is sufficient, but statement (2) alone is not sufficient.
(B) Statement (2) alone is sufficient, but statement (1) alone is not sufficient.
(C) BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
(D) Each statement ALONE is sufficient.
(E) Statements (1) and (2) TOGETHER are NOT sufficient.
491
ABCD is a rectangle, E is a point somewhere on side BC.
Is the area of triangle ABE > 25 ?

(1) AB = 6

(2) AE = 10



for triangle ABE, AB= 6, BE = 10, SO BE = 8. {right angle triangle}
area = 1/2*base*height
1/2*6*8 = 24

So answer is C.
492
ABCD is a rectangle, E is a point somewhere on side BC.
Is the area of triangle ABE > 25 ?

(1) AB = 6

(2) AE = 10

(A) Statement (1) alone is sufficient, but statement (2) alone is not sufficient.
(B) Statement (2) alone is sufficient, but statement (1) alone is not sufficient.
(C) BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
(D) Each statement ALONE is sufficient.
(E) Statements (1) and (2) TOGETHER are NOT sufficient.

IF we have AB = 6 , we can figure out that the pythagorean triplet pair would be (6,8 ,10)

Thus we know that 1/2 * 6 * 8 = 24
Thus Area is not > 25

Similarly using 2 we can say that when hyp is 10 , pyth triplet possible is (6,8,10)

Same reasoning , thus Area
Thus the answer is (D) Each statement ALONE is sufficient.
493

Plz help.... DS Question:

If N>0, is N a whole number?

1) 3N is an odd number
2) 2N is an even number

Regular options apply

494

Is the Answer (B)?

Plz help.... DS Question:

If N>0, is N a whole number?

1) 3N is an odd number
2) 2N is an even number

Regular options apply
495
Originally Posted by mittal.gaurav1 View Post
Plz help.... DS Question:

If N>0, is N a whole number?

1) 3N is an odd number
2) 2N is an even number

Regular options apply


Both are not sufficient to answer



1) 3N is an odd number ---> N can be negative or positive
2) 2N is an even number ---> N can be negative or positive

hence the answer
496
Both are not sufficient to answer

Originally Posted by mittal.gaurav1 (GMAT Data Sufficiency Discussions)" />"]
Plz help.... DS Question:

If N>0, is N a whole number?

1) 3N is an odd number
2) 2N is an even number

Regular options apply

1) 3N is an odd number ---> N can be negative or positive
2) 2N is an even number ---> N can be negative or positive

hence the answer


but the question says that N>0.

i guess the answere shoud be D
If we take first statement it says 3N is odd it means 3N is an integer
for 3N to be an intege N has to be an integer.

and for second statemnet
2N is even =>N is an intege(1,2,3...)

so answer should be D.
correct me if i am wrong." />
497
but the question says that N>0.

i guess the answere shoud be D
If we take first statement it says 3N is odd it means 3N is an integer
for 3N to be an intege N has to be an integer.

and for second statemnet
2N is even =>N is an intege(1,2,3...)

so answer should be D.
correct me if i am wrong.

Ans . B

Inder : "For 3N to be an intege N has to be an integer" -- this is not true.

3*(5/3) is an integer, but 5/3 is not an integer.
498
Ans . B

Inder : "For 3N to be an intege N has to be an integer" -- this is not true.

3*(5/3) is an integer, but 5/3 is not an integer.



ya you are right Vicky.
thanks a lot
499
1. If digit h is the hundredths' digit in the decimal d=0.2h6, what is the value of d, rounded to the nearest tenth?
(1) d
(2) h
2.If*represents one of the operations +, -, and , is k*(l+m)=(k*l)+(k*m) for all numbers k,land m?
(1) k*l is not equal to l*k for some numbers k.
(2) *represents subtraction.

Both OA are D.......pls help with reasoning.....
500
Plz help.... DS Question:

If N>0, is N a whole number?

1) 3N is an odd number
2) 2N is an even number

Regular options apply


The answer is B. Can u give me an explanation?