Aptitude - Average - Discussion

Discussion Forum : Average - General Questions (Q.No. 11)
11.
The average weight of A, B and C is 45 kg. If the average weight of A and B be 40 kg and that of B and C be 43 kg, then the weight of B is:
17 kg
20 kg
26 kg
31 kg
Answer: Option
Explanation:

Let A, B, C represent their respective weights. Then, we have:

A + B + C = (45 x 3) = 135 .... (i)

A + B = (40 x 2) = 80 .... (ii)

B + C = (43 x 2) = 86 ....(iii)

Adding (ii) and (iii), we get: A + 2B + C = 166 .... (iv)

Subtracting (i) from (iv), we get : B = 31.

B's weight = 31 kg.

Discussion:
40 comments Page 2 of 4.

Ganeshgore said:   8 years ago
Thanks @Kaustubh.
(1)

BHUWAN JOSHI said:   7 years ago
@Shree Hema.
135-86 = 49 not 41,
than 49+ B=80,
So, B=31 Years.

Sara said:   9 years ago
Thanks, @Krishna. Your explanation was useful.

Sandeep said:   5 years ago
Thanks @Shree Hema.

THORAT SANDIP said:   8 years ago
A+B+C=135......(1)
B+C=86.....(2)
SUBTRACT EQ. 2 FROM 1, WE GET.
(A+B+C)-(B+C)=135-86=49.
A=49.
A+B=80.....(3).

PUT THE VALUE OF A IN ABOVE EQUATION.
49+B=80,
B=80-49=31.

Medha said:   8 years ago
B + c = 86 ( 1)
A + B + C = 135 (2)
A + B = 80 (3)

Substituting (1) in (2)
A = 135 - 86 = 49.

From (3):
B = 80 - 49 = 31.

Anjum said:   8 years ago
Thanks everyone for helping it by giving the explanation.

Ayisha said:   9 years ago
Exactly right. Thank you all.

Anjum said:   9 years ago
Thanks, it is easy to access the answers.

Faisal said:   9 years ago
Thanks @Priyanka.


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