angry.birds wrote:Hi,
Can someone please answer this?
If the quotient of a/b is positive, which of the following must be true?
1. a>o
2. b>0
3. ab>0
4. a-b>0
5. a+b>0
I am stuck between 1,2 and 3. I know 3 will be true always but somehow cant seem to get why is 1 or 2 wrong?
If I assume my dividend = 6 (a), divisor = -3 (b), then also my quotient will be positive (2). I am not sure if the question is talking about the entire expression (a/b) being positive or the quotient being positive.
If the quotient has to be positive it will hold true when my b is negative and a is positive. Similarly, if i assume my dividend to be -6 and divisor to be 3. then also my quotient will be positive.
Am I missing something here?
Try to show that the answers DON'T have to be true.
Let a = -2, b = -1.
a/b = (-2)/(-1) = 2, yielding a positive quotient.
Now plug a = -2 and b = -1 into the answers.
Eliminate any answer choices that are not true when a=-2 and b=-1.
A: -2>0. Not true. Eliminate A
B: -1>0. Not true. Eliminate B.
C: (-2)(-1) > 0. True. Hold onto C.
D: -2-(-1) > 0. Not true. Eliminate D.
E: -2+(-1) > 0. Not true. Eliminate E.
The correct answer is
C.
Quotient = the result of division.
For the quotient of a and b to be positive, a and b must have the same sign.
Since (positive)*(positive)>0 and (negative)*(negative)>0, answer choice
C must be true.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.
As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.
For more information, please email me (Mitch Hunt) at
[email protected].
Student Review #1
Student Review #2
Student Review #3
