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If a − c = 17, b − a = 12 and 2a + b + 3c = 7, then what is the value
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17 May 2021, 15:14
17 May 2021, 15:14
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If a − c = 17, b − a = 12 and 2a + b + 3c = 7, then what is the value of a + b + c ?
A) 2
B) 6
C) 9
D) 12
E) 18
A) 2
B) 6
C) 9
D) 12
E) 18
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Status:GRE Quant Tutor
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Given Kudos: 9
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Concentration: General Management
Schools: XLRI Jamshedpur, India - Class of 2014
GMAT 1: 700 Q51 V31
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WE:Engineering (Computer Software)
If a c = 17, b a = 12 and 2a + b + 3c = 7, then what is the value
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18 May 2021, 07:53
18 May 2021, 07:53
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Usually in these kind of questions where you have a lot of equations then you just need to add all the equations to get the result
a − c = 17
b − a = 12
2a + b + 3c = 7
Adding all three of them we get
a − c + b − a + 2a + b + 3c = 17 + 12+ 7 = 36
=> 2a + 2b + 2c = 36
=> 2(a+b+c) = 36
=> a+b+c = 36/2 = 18
So, Answer will be E.
Hope it helps!
a − c = 17
b − a = 12
2a + b + 3c = 7
Adding all three of them we get
a − c + b − a + 2a + b + 3c = 17 + 12+ 7 = 36
=> 2a + 2b + 2c = 36
=> 2(a+b+c) = 36
=> a+b+c = 36/2 = 18
So, Answer will be E.
Hope it helps!
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Joined: 10 Apr 2015
Posts: 6218
Given Kudos: 136
Re: If a − c = 17, b − a = 12 and 2a + b + 3c = 7, then what is the value
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12 Nov 2021, 11:04
12 Nov 2021, 11:04
Carcass wrote:
If a − c = 17, b − a = 12 and 2a + b + 3c = 7, then what is the value of a + b + c ?
A) 2
B) 6
C) 9
D) 12
E) 18
A) 2
B) 6
C) 9
D) 12
E) 18
Take the 3 equations and add them to get: (a − c) + (b − a) + (2a + b + 3c) = 17 +12 + 7
Simplify: 2a +2b + 2c = 36
Divide both sides by 2 to get: a + b + c = 18
Answer: E
