I am getting B)
Given : a+b > -c
a+b+c>0
Find: Is a > 2?
Stmt I
a+b+c > 8
a=-10000 b=2000000 c=300000000
a>2 no
a=5 b=1 c=3 a+b+c>8 a>2 YES
INSUFF
Stmt II
a+b+c>0
– a + b + c < – 4
b+c+4<a
b+c < a-4 i.e a-4 > b+c ( I )
a+b+c>0
a> -b-c ( II )
Add I and II
2a-4>0
2a > 4
a>2
SUFF
Choose B)
inequality trap
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cramya
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I know we can add inequalities facing same direction without affecting the combined inequality.Stmt II: – a + b + c < – 4
Rearrange given as a+b+c>0 and then substract Stmt II from it
2a>4
a>2
It comes out what we need to find but not sure if u can subtract inequalities facing different directio?
Thoughts anyone?
Regards,
CR
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ronniecoleman
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IMO B
A+ B+ C > 0
B+ C > -A ------1
B+ C+ 4 < A
Replace B+ C by -A
-A+ 4 < A
A > 2
A+ B+ C > 0
B+ C > -A ------1
B+ C+ 4 < A
Replace B+ C by -A
-A+ 4 < A
A > 2
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logitech
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cramya wrote:I know we can add inequalities facing same direction without affecting the combined inequality.Stmt II: – a + b + c < – 4
Rearrange given as a+b+c>0 and then substract Stmt II from it
2a>4
a>2
It comes out what we need to find but not sure if u can subtract inequalities facing different directio?
Thoughts anyone?
Cramya never ever perform an operation when the INEQS are facing different directions.
But if they are facing the same directions..I STILL WILL BE VERY CAREFUL!
-(-a) = +a
Regards,
CR
LGTCH
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adilka
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Here is how it works:cramya wrote:I know we can add inequalities facing same direction without affecting the combined inequality.Stmt II: – a + b + c < – 4
Rearrange given as a+b+c>0 and then substract Stmt II from it
2a>4
a>2
It comes out what we need to find but not sure if u can subtract inequalities facing different directio?
Thoughts anyone?
Regards,
CR
Given: a+b+c>0
Stmt II: – a + b + c < – 4 can be rearranged as a-b-c>4 (basically, multiply by -1)
Hence:
a+b+c>0
a-b-c>4
add them together, you get 2a>4
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Ian Stewart
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Yes, but when you subtract inequalities that face in opposite directions, you're really just doing the following:cramya wrote:I know we can add inequalities facing same direction without affecting the combined inequality.Stmt II: – a + b + c < – 4
Rearrange given as a+b+c>0 and then substract Stmt II from it
2a>4
a>2
It comes out what we need to find but not sure if u can subtract inequalities facing different directio?
Thoughts anyone?
Regards,
CR
-multiplying one of the inequalities by -1 on both sides, *reversing* the inequality (so they now face in the same direction);
-adding the two inequalities together.
I've never bothered to learn rules for subtracting inequalities, and I always do the steps above; it's the only way I feel confident about each step.
For online GMAT math tutoring, or to buy my higher-level Quant books and problem sets, contact me at ianstewartgmat at gmail.com
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aj5105
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very cool..
cramya wrote:I am getting B)
Given : a+b > -c
a+b+c>0
Find: Is a > 2?
Stmt I
a+b+c > 8
a=-10000 b=2000000 c=300000000
a>2 no
a=5 b=1 c=3 a+b+c>8 a>2 YES
INSUFF
Stmt II
a+b+c>0
– a + b + c < – 4
b+c+4<a
b+c < a-4 i.e a-4 > b+c ( I )
a+b+c>0
a> -b-c ( II )
Add I and II
2a-4>0
2a > 4
a>2
SUFF
Choose B)
