Is m+10 positive?

Question

Is m+10 positive?

(1) On the number line, m+10 is closer to 0 than to m.

(2) On the number line, m-10 is closer to 0 than to m.

chetan2u · Answer

Read the Q as following and solution would be

Quote:

Is m+10 positive?

(1) On the number line, 0 is closer to m+10 than to m.

(2) On the number line, 0 is closer to m-10 than to m.

answer would depend on value of m

(1) On the number line, 0 is closer to m+10 than to m.
m+10 will be > m .....
so if \(m<\frac{-10}{2}\) that is m<-5, so m+10 can take BOTH positive and negative values
m+10=3...m=-7 so TRUE
m+10=-10...m=-20...TRUE again
Insuff

(2) On the number line, 0 is closer to m-10 than to m
m-10 will always be on LEFT side of m..
so if \(m>\frac{10}{2}\) that is m>5, so m+10 can take ONLY positive values
ans YES
sufficient

B

Note: sandysilva, although the Q is tricky but NOT accurate.
In GMAT, you can't have different values of m..
statement I gives you m<-5 and II gives you m>5.. NO overlapping region

er.arun88 · Answer

Hi Chetan, Can you please explain why option 1 is insuff?
Ques is just asking whther m is +ive or not
the examples you have taken also shows m will remain negative always.
am i missing something?

DAVEexamPAL · Answer

er.arun88  if m<-5, then m can be, say, -6, in which case m+10 is 4. 
So it can be either positive or negative.

chetan2u · Answer

hi Arun,

the Q is asking whether m+10 is POSITIVE or not..
YES m here will always be -ive, but m+10 can be anything..
m is anything -100000000... to -10, m+10 will be closer to 0 but m+10 will be <0
but m between -10 and -5 will give m+10 as positive and also m+10 will be closer to 0 than m is..

Bunuel · Answer

Is m + 10 positive?

Is m + 10 > 0;
Is m > -10.

(1) On the number line, m + 10 is closer to 0 than to m.

The distance between m + 10 and 0 is |m + 10 - 0| = |m + 10|;
The distance between m + 10 and m is |m + 10 - m| = |10| = 10.

We are told that |m + 10| < 10;
-10 < m + 10 < 10;
-20 < m < 0.

Not sufficient.

(2) On the number line, m - 10 is closer to 0 than to m.

The distance between m - 10 and 0 is |m - 10 - 0| = |m - 10|;
The distance between m - 10 and m is |m - 10 - m| = |-10| = 10.

We are told that |m - 10| < 10;
-10 < m - 10 < 10;
0 < m < 20.

Sufficient.

Technically answer should be B, as statement (2) ALONE is sufficient, but statement (1) alone is not sufficient to answer the question asked.

But even though formal answer to the question is B, this is not a realistic GMAT question, as: on the GMAT, two data sufficiency statements always provide TRUE information and these statements never contradict each other. But the statements above contradict each other:
From (1) -20 < m < 0 and from (2) 0 < m < 20. The statements clearly contradict each other.

So, the question is flawed. You won't see such a question on the test.

chetan2u · Answer

A question on same lines with correct statements could be..
 https://gmatclub.com/forum/is-x-positive-255673.html

sandysilva · Answer

This is one of the Experts Global Cat questions.

Is m+10 positive?

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GMAT Data Sufficiency (DS) Questions

Is m+10 positive?

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