GMAT Data Sufficiency Discussions

MBA GMAT
161
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..


Mate! With option B let us assume some values
t = -10
s = -20
r = -40

now, -s = 20 so the distances between "t and s" and "s and r" are equal. :smile:
with condition (a) it assures that the value of t and s are positive.

Hope it helps,

Cheers,
Sumit
162
answer is C man..let us assume tht bob produced 'y' articles last week..using st.1 last week he earned:

x + 1.5x(y-36) = 480

using st.2,
this week, he earned :
x + 1.5x(y-34) = 510
solve both eq. and u can get the answer


your approch to this is assuming both are above 36.

both can be below 36 as well. in that case statements can be re written as y*x=480 and (y+2)*x=510 solving x=15 and y=32 y+2 =34

there is also has another case one number is equal or below 36 and one number is sbove 36. But such case has no solution.
163

Hi Puys,

Came across a few question in GMATPrep which i cudn't solve. Please check the attached document.

Thanks in advance.

164
Hi Puys,

Came across a few question in GMATPrep which i cudn't solve. Please check the attached document.

Thanks in advance.


Hi sachin_h,

To simplify:
Slope of a line is positive when its orientation is NE-SW
Slope of a line is negative when its orientation is NW-SE

I thought its best to explain this problem pictorially. Plz see the attached jpg image.
165

@sachin_h

Soln for ur 2nd doubt:
From the question stem, we understand
450 350
St 1: x when y = 449, x+y = 900 ie.closer to 900
when y = 351, x+y = 802 ie.closer to 800
Hence, insufficent

St 2: y when x = 549, x+y = 900 ie.closer to 900
when x = 451, x+y = 802 ie.closer to 800
Hence, insufficent

Combining the 2 statements,
case 1: x=451, y =351 x+y = 802 ie.closer to 800
case 2: x=499, y=399 x+y = 898 ie.closer to 900
Insufficent again

Hence answer E.

If u havent understood the solutions, plz PM me.

All the best for 12th.

166

guyz ne suggestions for da DS...especialy for questions like:

iz m+z>0

1) m-3z>0
2) 4z-m>0


i chose "E" which kinda looked obvoius ...

any suggestions while guessing..or any other trciks...i usually stumble upon DS
thx

167
guyz ne suggestions for da DS...especialy for
i chose "E" which kinda looked obvoius ...

any suggestions while guessing..or any other trciks...i usually stumble upon DS
thx


Well I think that the answer is C.

Expln:

Suppose we have "M" no. of managers and "D" no. of Directors, with the avg salary of the group (M+D) = t.

So with choice 1 => Avg salary of managers = t-5; NOT SUFFICIENT
and with choice 2 => avg slary of Directors = t+15; NOT SUFFICIENT

Now with choice 1 and choice 2, together:

Total Salary for the group = (Total salary of Managers) + (Total salary of directors)

(M+D)t = M(t-5) + D(t+15)
or, (Mt + Dt) = (Mt + Dt - 5M + 15D)
or, 5M = 15D
or M/D = 3;

Hence, sufficient.

Answer: C

Cheers,
Sumit
168
guyz ne suggestions for da DS...especialy for questions like:

iz m+z>0

1) m-3z>0
2) 4z-m>0


i chose "E" which kinda looked obvoius ...

any suggestions while guessing..or any other trciks...i usually stumble upon DS
thx

This question. using bot staeemnts
add both u get z>0. now using staement 1 u willget m>3z means m is also positive. so m+z >0.. Anw is C
169
ATTN all!!!
ZERO is a multiple of any number and it is included in the list of multiples of a number...i verified this while giving the Full length test of Kaplan Premier Edition in the book....
170

I got this question wrong in GMATPREP. Even after seeing the answer, i couldnt get how it is.
Can u pls take a look and try and answer - with explaination

I took GMATPREP and there are some questions which were wrong. I would like them post them here. Try, answer and explain why it it is the answer.

DS:

1. Is Sqrt (x-3) = 3-x

A) x is not equal to 3
B) x*(MOD x)

171
I got this question wrong in GMATPREP. Even after seeing the answer, i couldnt get how it is.
Can u pls take a look and try and answer - with explaination

I took GMATPREP and there are some questions which were wrong. I would like them post them here. Try, answer and explain why it it is the answer.

DS:

1. Is Sqrt (x-3) = 3-x

A) x is not equal to 3
B) x*(MOD x)
if sqrt(x-3)=3-x, then x-3=9-6x+x2
x2-7x+12=0
so question is askin whether x2-7x+12 = 0
which is possible only if x=3 or x=4

so A is nt sufficient to answer because x can be equal to 4 also...
st.B tells us that x is a -ve number since x Mod(x)so answer is B.
172

I am sorry..small modification in question
1. Is Sqrt = 3-x

A) x is not equal to 3
B) x*(MOD x)

173

Is the answer B? I mean we can tell from the B option alone that if x is negative then sqrt of sqr(-x-3) will be same as (3-(-x)).

174

answer is B.
But how can we say if SQRT is = 3-x ??

175

If x is a -ve integer, as derived form second option, then if you substitute the value of x as (-x) in SQRT(sqr(x-3)) will be +ve(-x-3) which is same as (3-(-x)).

176
I am sorry..small modification in question
1. Is Sqrt = 3-x

A) x is not equal to 3
B) x*(MOD x)

Hi Answer is D
with statement A X is not equal to 3
if x>3 then 3-x is -ve and sqrt(sqrt(x-3) cnnot take -ve value.
if x is less than sqrt (sqrt(x-3) is an imaginary number ,on the other hand 3-x is a real number.
using the statement A alone we can conclude that both are not equal.
Now using staement B alosne. we can say x is a -ve number
so LHS is an imaginary number and RHS is a real number. so both are not equal.
both are equal only when x=3
177
Hi Answer is D
with statement A X is not equal to 3
if x>3 then 3-x is -ve and sqrt(sqrt(x-3) cnnot take -ve value.
if x is less than sqrt (sqrt(x-3) is an imaginary number ,on the other hand 3-x is a real number.
using the statement A alone we can conclude that both are not equal.
Now using staement B alosne. we can say x is a -ve number
so LHS is an imaginary number and RHS is a real number. so both are not equal.
both are equal only when x=3


It is SQRT , its NOT SQRT
178

One more DS.
A certain 1 day seminar consisted a morning session and an afternoon session. If each of ppl attending seminar attended at least one seminar, how many attended morning session only.
A. 3/4 people attended both seminars
B. 7/8 attended afternoon session

179
One more DS.
A certain 1 day seminar consisted a morning session and an afternoon session. If each of ppl attending seminar attended at least one seminar, how many attended morning session only.
A. 3/4 people attended both seminars
B. 7/8 attended afternoon session


howz E?........seems suitable as no data is given
180

Actual answer is B.
this question i got in GMATPREP. I too answered E because no way we can determine from the info given. I got 710 in GMATPREP at last ,and i got this question between q.no 20 and 25.

But i could nt understand how it can be B