What is the average (arithmetic mean) of a, b, and c ?

Question

(1) a + 2b + 3c = 10

(2) 3a + 2b + c = 14

niks18 · Answer

Basically we need the value of  a+b+c , to determine the average

Statement 1:   a+2b+3c=10  cannot be factorized to get  a+b+c .  Insufficient

Statement 2:   3a+2b+c=14  cannot be factorized to get  a+b+c .  Insufficient

Combining 1 & 2:  add the two equations to get  4a+4b+4c=24 => a+b+c=6 .  Sufficient

Option  C

PKN · Answer

Combining (1) (2), we have
a + 2b + 3c +3a + 2b + c =4(a+b+c)=24
Now, AM(a,b,c)= \frac{(a+b+c)}{3} = \frac{24}{4*3} 
So, AM of a,b, and c is 2.
Sufficient.

Ans. (C)

PKGMAT · Answer

Avg=(a+b+c)/3

From Equation A, we neither find value of individual variable(a,b,c) nor we can find the sum (a+b+b+c)

From Equation B also we can not find value of individual variable(a,b,c) or the sum (a+b+b+c)

Using both equation:-
4(a+b+c)=10;
=> (a+b+c)=10/4

so the avg will be 10/12

PKN · Answer

Hi  PKGMAT ,
4(a+b+c)=10+14=24.

Posted from my mobile device

CareerGeek · Answer

(1) a + 2b + 3c = 10

Insufficient

(2) 3a + 2b + c = 14

Insufficient

Combining (1) & (2),

Adding both equations,
—> 4a + 4b + 4c = 24
—> a + b + c = 6

Average = 6/3 = 2

Sufficient

Option C

Posted from my mobile device

KanikaJain · Answer

What is the average (arithmetic mean) of a, b, and c ?

(1) a + 2b + 3c = 10

(2) 3a + 2b + c = 14

Statement 1:
Diving by 3: (a+2b)/3 + c = 3.33

Statement 2:
Diving by 3: (c+2b)/3 + a = 4.66

Now adding: 4a + 4b + 4c = 24. thus a+b+c = 6

Thus C

What is the average (arithmetic mean) of a, b, and c ?

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