[bhavin422]

Originally Posted by xyz3000

Q2: On the number line shown, is 0 halfway between r and s ?
1) s is to the right of 0.
2) The distance between t and r is the same as the distance between t and -s.

<------r----------s---t------> (This is a number line with r, s and t placed on it)


2. |t-r| = |t+s|, find whether r+s = 0

square it, t^2 + r^2 - 2rt = t^2 + s^2 + 2ts
(r+s)(r-s-2t) = 0
either r+s = 0 or r - s = 2t

r-s = 2t --> r-t = t -s. In other words, t gotta be in between r and s.
The diagram shows that t is not in between and r and s.

Therefore r - s <> 2t. therefore, r +s = 0. Sufficient.


Answer is B

Hey Statement in bold is incorrect ...
Check the solution here :
http://www.pagalguy.com/forum/gmat-a...ml#post1698626 (GMAT Data Sufficiency Discussions)

Hope that helps !

[xyz3000]

Originally Posted by bhavin422

Hey Statement in bold is incorrect ...
Check the solution here :
http://www.pagalguy.com/forum/gmat-a...ml#post1698626 (GMAT Data Sufficiency Discussions)

Hope that helps !

Thanks, I know where I made a mistake.

I can't conclude "t has to be in between s and t" when r - s = 2t, unless r, s, and t have same signs. This assumption is not given in (2).

[xyz3000]

Q. Is x^4 + y^4 > z^4 ?

a) x^2 + y^2 > z^2
b) x+ y > z

let x/z =a, y/z =b

Is a^4 + b^4 > 1

1. a^2 + b^2 > 1
2. a + b > 1


1. a^2 + b^2 > 1 ==> a^4 + b^4 > 1 - 2 a^2 b^2.

There are cases where a^4 + b^4 < 1. Insufficient.

2. a + b > 1, a^2 + b^2 > 1 - 2ab, a^4 + b^4 > 1 + 2a^2 b^2 - 4ab
Insufficient because of "-4ab"

Combining together gives a^2 + b^2 > 1 - 2ab. Insuff.

E

[arungeorge101]

I found this question in OG 12th edition.
My question is:

what is the perimeter of an isosceles triangle MNP?
1. MN = 16
2. NP = 20

now the answer given for this question is E. But now the perimeter is

P = MN + MP + NP = 2MN + NP

with 1 alone we cannot get the answer, but with 1 & 2 we can easily get the answer by applying the basic theorem "The sum of the lengths of any two sides of a triangle must be greater than the third side." So aint the answer C?

Am I making sense?

P.S:I am new to this site and this is my first post. If am not followign any conventional rules of this forum, kindly excuse.

[debasis08]

my answer is E because from the 2 statement it is not mention that which 2 sides are equal.. it may either equal to MN or Np..

[Nipunbans]

But how do you know that MN is the isosceles side??? It can be other side too..
I mean perimeter can be 16+16+20 or 20+20+16. both are equally correct... So E!!

Originally Posted by arungeorge101

I found this question in OG 12th edition.
My question is:

what is the perimeter of an isosceles triangle MNP?
1. MN = 16
2. NP = 20

now the answer given for this question is E. But now the perimeter is

P = MN + MP + NP = 2MN + NP

with 1 alone we cannot get the answer, but with 1 & 2 we can easily get the answer by applying the basic theorem "The sum of the lengths of any two sides of a triangle must be greater than the third side." So aint the answer C?

Am I making sense?

P.S:I am new to this site and this is my first post. If am not followign any conventional rules of this forum, kindly excuse.

[neha.visionary]

How many integers n are there such that r<n<s?

1) s-r=5
2) r and s are not integers.


Regards,
Neha

[bhavin422]

Originally Posted by neha.visionary

How many integers n are there such that r<n<s?

1) s-r=5
2) r and s are not integers.


Regards,
Neha

IMO Ans C ...

St 1 : if r and s are integers, there are another 4 integers between them.
Eg 4 int between 5 and 10
If r and s are not integers then there are 5 integers between them
Eg 5 int between 4.5 and 9.5

Not suff...

St 2 : tells us nothing ..not suff ...

Combined : there have to be 5 integers between r and s ...suff
Ans C

[neha.visionary]

Originally Posted by bhavin422

IMO Ans C ...

St 1 : if r and s are integers, there are another 4 integers between them.
Eg 4 int between 5 and 10
If r and s are not integers then there are 5 integers between them
Eg 5 int between 4.5 and 9.5

Not suff...

St 2 : tells us nothing ..not suff ...

Combined : there have to be 5 integers between r and s ...suff
Ans C

Thanks. the OA is C.
when i solved couldn't understand why there are 4 int b/w 5 and 10. and5 b/w 4.5 and 9.5.
thanks for explaining.


Regards,
Neha

[gradpostgrad23]

Hi Puys, This question already been explained before but I couldn't understand the explanation given. Please help me out. Thanks for the help.

Is mod (x) < 1 ?

(1) ⏐mod (x + 1)⏐ = 2 mod (x - 1)⏐
(2) ⏐mod (x - 3)⏐ ≠ 0

Is it A?