GMAT Data Sufficiency Discussions

well..i guess the answer is E...
considering st.1,
there cud be 4 possible cases..
case 1:
(x+1) = 2(x-1)
hence, x=3
case 2:
(x+1) = 2* -(x-1)
hence, x=1/3
thus, u dont get a unique answer..

considering st.2,
since mod(x-3)0,
x can take any value except 3..thus, x can be 0, 1, 2, 4,...
thus, st.2 is also nt sufficient

i think ans should be A,

the qn is asking ,is -1
from first statement:
the possible regions of inequality are -1
1,x checking the inequality against these'
in the region -1
in the region x>1, x=1/3 ,not in the region
in region x
thus x=1/3 is the only solution

and from 2nd statement we know that x is not equal to 3

not suff.
well..i guess the answer is E...
considering st.1,
there cud be 4 possible cases..
case 1:
(x+1) = 2(x-1)
hence, x=3
case 2:
(x+1) = 2* -(x-1)
hence, x=1/3
thus, u dont get a unique answer..

considering st.2,
since mod(x-3)0,
x can take any value except 3..thus, x can be 0, 1, 2, 4,...
thus, st.2 is also nt sufficient




Ajay I think the answer must be C .
Since from st 1 we know x = either 3 or 1/3
and stmt 2 we know x3
So from 1 & 2 together. x=1/3 Therefore mod(x)
Plz correct me If I am wrong
Thats why the answer is E and not C.
because the extra item costs Rs 15/- . that can mean 510/15 = 34 items
or
360/10 = 36 items and 150/15 = 10 items ie total 46 items

Thus the total no of items cannot be determined.


Are u sure that answer is E???

I think the answer has to be C

cost of 2 extra items = 510-480 = 30 =>cost of each extra item = 15 => 1.5 x=15
=>x=10
now for total item y

36*10 + 15(y-36)= 480
y = 44

or
360 + 15(y-34)= 510
=>y=44
Ajay I think the answer must be C .
Since from st 1 we know x = either 3 or 1/3
and stmt 2 we know x3
So from 1 & 2 together. x=1/3 Therefore mod(x)
Plz correct me If I am wrong

it should be A ,as frm statement 1 we get only x=1/3, x=3 is not in the range for x if i am not missing something.
it should be A ,as frm statement 1 we get only x=1/3, x=3 is not in the range for x if i am not missing something.


But since in st1 we find out that x can be either 1/3 or 3 . it is only in st2 we get info which says x != 3.
so only when we take the stmt 2 into consideration can we narrow down on 1/3 .
Plz correct me if wrong . wats the answer by the way
But since in st1 we find out that x can be either 1/3 or 3 . it is only in st2 we get info which says x != 3.
so only when we take the stmt 2 into consideration can we narrow down on 1/3 .
Plz correct me if wrong . wats the answer by the way

from statement 1 we get x = 1/3 only
as when we get x=3 the range we are taking is x also we get x=1/3 for range x > 1 which again doesnt satisfy the solution.so.
we get x=1/3 for range -1there are three ranges for the given equation
x1,-1
from statement 1 we get x = 1/3 only
as when we get x=3 the range we are taking is x also we get x=1/3 for range x > 1 which again doesnt satisfy the solution.so.
we get x=1/3 for range -1there are three ranges for the given equation
x1,-1

ankaccent and sharkon...this problem itself is confusing...a first look at the problem and we know tht the problem is asking whether mod(x)
Is mod (x)
(1) mod (x + 1) = 2 mod (x - 1)
(2) mod (x - 3) 0



Ans. is C .

Thanks

can any body assist in solving this problem..
data sufficiency question



question is in above number line is zero half way between s and r ?

a. s is to the right of zero.

b. distance between t and -s is same as distance between t and r.


in above case...ans is c both and b.

my doubt..only b should suffice..

can anybody elobrate..

can any body assist in solving this problem..
data sufficiency question



question is in above number line is zero half way between s and r ?

a. s is to the right of zero.

b. distance between t and -s is same as distance between t and r.


in above case...ans is c both and b.

my doubt..only b should suffice..

can anybody elobrate..

the answer is ofcourse C...because, st.1 just tells us that 0 is to the right of s..so it can be anywher within r and s or beyond r...
st.2 tells us that dist. between t and -s is same as dist. between t and r...this does not tell us the location of zero..so this option is useless...
considering both the options, dist. between t and -s will be same as dist. between t and r only if r = -s...this can be concluded because we know zero is to the left of s..hence s is +ve..thus, r has to be equal to -s for the condition to hold true..
Are u sure that answer is E???

I think the answer has to be C

cost of 2 extra items = 510-480 = 30 =>cost of each extra item = 15 => 1.5 x=15
=>x=10
now for total item y

36*10 + 15(y-36)= 480
y = 44

or
360 + 15(y-34)= 510
=>y=44


I give you 2 pairs satisfing both conditions.
32,34 x=15
44,46 X=10
So anwer is E
can any body assist in solving this problem..
data sufficiency question



question is in above number line is zero half way between s and r ?

a. s is to the right of zero.

b. distance between t and -s is same as distance between t and r.


in above case...ans is c both and b.

my doubt..only b should suffice..

can anybody elobrate..


The Answer must be C only.


The reason it is not B is as follows:


1)Suppose s,r,t are all to the left of Zero ie all are -ve
then there is a chance that dist b/w TR is equal to distance b/w T and -S (-S will be +ve and to the Right of Zero).

Hence without knowing S is +ve or -ve it is hard to answer question using B only
considering option 1:

since the greatest common factor of both the nos. is 2, it means tht the nos. cud be 4&6, 4&10, 6&10 etc...divide any two such nos. and the remainder will always be greater than 1..infact, i think in most cases it is exactly 2...hence, this statement is sufficient to answer the question

option 2 :

the LCM is 30...so the nos. cud be 6&10, 3&10, 15&30, 3&30, 6&30 etc... and try dividing any of these combinations, the remainder will always be greater than 1....this statement is also sufficient on its own to answer the question.
so the answer is C

here as we can see that numbers 3 and 10 when 10 divided by 3 we get remainder as 1 so answer choice is a, not c
The Answer must be C only.


The reason it is not B is as follows:


1)Suppose s,r,t are all to the left of Zero ie all are -ve
then there is a chance that dist b/w TR is equal to distance b/w T and -S (-S will be +ve and to the Right of Zero).

Hence without knowing S is +ve or -ve it is hard to answer question using B only


Hi With clue b alone you can draw the above diagram (forget zero inthe diagram) which says r is not between s and -s .. Zero is always between s and -s . with this you can always say zero is not in between r and s . so anwer is B
see, the equation can be rewritten as :
x
1 - when y>0, take any value of y>0...2,3,4....the corresponding values of x will be x
2 - we are given that x

y-20 = 0...y = 20....x = -40
-8y-20 = 0...y = -20/8....x = -60/8

hence, the value of x will always be less than 0...
thus statement 2 is also sufficient to answer on its own


i sugget simple approach to this problem for 2 stem...

we know that -2x>3y, 2x+5y=20 here by substituting y in terms of x in inequality, we can find that x
any other approach will be highly appreciated..:grab:
see, the equation can be rewritten as :
x
1 - when y>0, take any value of y>0...2,3,4....the corresponding values of x will be x
2 - we are given that x

y-20 = 0...y = 20....x = -40
-8y-20 = 0...y = -20/8....x = -60/8

hence, the value of x will always be less than 0...
thus statement 2 is also sufficient to answer on its own

Sriram_Avadhani Says
Hi With clue b alone you can draw the above diagram (forget zero inthe diagram) which says r is not between s and -s .. Zero is always between s and -s . with this you can always say zero is not in between r and s . so anwer is B



no...

answer c is correct...even i assumd that variables r,s,t as positive...
we cannot say that variable x is +ve no and -x is -ve no, it may be possible that x is -ve and -x is +ve..

if you contend , we can discuss further....
I give you 2 pairs satisfing both conditions.
32,34 x=15
44,46 X=10
So anwer is E

plz refer to this post and tell me wher i hv gone wrong, if at all.

http://www.pagalguy.com/discussions/gmat-data-sufficiency-discussions-25020702
the answer is ofcourse C...because, st.1 just tells us that 0 is to the right of s..so it can be anywher within r and s or beyond r...
st.2 tells us that dist. between t and -s is same as dist. between t and r...this does not tell us the location of zero..so this option is useless...
considering both the options, dist. between t and -s will be same as dist. between t and r only if r = -s...this can be concluded because we know zero is to the left of s..hence s is +ve..thus, r has to be equal to -s for the condition to hold true..

see, i can further explain why st. b is nt sufficient on its own..
if zero lies to the right of 't' , then 's' is -ve...thus, -s will be +ve value of s...but, if zero lies midway between r and s, then r = -s...still the condition is satisfied..thus, u dont get a unique location for zero..thts why the answer's C
Sriram_Avadhani Says
Hi With clue b alone you can draw the above diagram (forget zero inthe diagram) which says r is not between s and -s .. Zero is always between s and -s . with this you can always say zero is not in between r and s . so anwer is B

see, i can further explain why st. b is nt sufficient on its own..
if zero lies to the right of 't' , then 's' is -ve...thus, -s will be +ve value of s...but, if zero lies midway between r and s, then r = -s...still the condition is satisfied..thus, u dont get a unique location for zero..thts why the answer's C
1) n^2=I =>n=+SQRT(I) and -SQRT(I) . Now if SQRT(I) is either irrational or integer
since SQRT(I) = p/q =>not an irrational no. =>SQRT(I) is an integer =>n is an integer.

2)(n+1)/2 =I =>n=2I-1 =>n is an integer

Therefore Ans is D .Do let me know if I am right.

well explained....