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:
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 1 of 4.
Mizan Ahmad said:
8 months ago
A + B + C = 45 * 3 = 135-----> eq(1)
A + B = 40 * 2 = 80---------> eq(2)
B + C = 43 * 2 = 86----------> eq(3)
Using eq(1) & eq(3)
(A) + (B+C) = 135
A + 86 = 135
A = 135 - 86
= 49.
By using eq(2)
A + B = 80.
49 + B = 80.
B= 80-49
Ans =31.
A + B = 40 * 2 = 80---------> eq(2)
B + C = 43 * 2 = 86----------> eq(3)
Using eq(1) & eq(3)
(A) + (B+C) = 135
A + 86 = 135
A = 135 - 86
= 49.
By using eq(2)
A + B = 80.
49 + B = 80.
B= 80-49
Ans =31.
(5)
Dharshni said:
1 year ago
A + b + c = 45 * 3 = 135
A + b = 40 * 2 = 80.
B + c = 43 * 2 = 86.
Now.
(A+b)(b+c) = 80 + 86.
= 166.
166 - 135.
= 31kg.
A + b = 40 * 2 = 80.
B + c = 43 * 2 = 86.
Now.
(A+b)(b+c) = 80 + 86.
= 166.
166 - 135.
= 31kg.
(12)
Abhijeet said:
1 year ago
Let consider 3 Equation are there:
a + b + c = 45
a + b = 40
b + c = 43
Let multiply the average of the equation by the number of persons.
a + b + c = 45 * 3 = 135 -----> 1
a + b = 40 * 2 = 80 ----->2
b + c = 43 * 2 = 86 ---->3
Now put equation 2 in 1.
80 + c = 135.
c = 135 - 80 = 55.
Put the value of c in Equation 3.
b + 55 = 86,
b = 86 -55.
b = 31 hence the average of B is 31 i.e option D.
a + b + c = 45
a + b = 40
b + c = 43
Let multiply the average of the equation by the number of persons.
a + b + c = 45 * 3 = 135 -----> 1
a + b = 40 * 2 = 80 ----->2
b + c = 43 * 2 = 86 ---->3
Now put equation 2 in 1.
80 + c = 135.
c = 135 - 80 = 55.
Put the value of c in Equation 3.
b + 55 = 86,
b = 86 -55.
b = 31 hence the average of B is 31 i.e option D.
(14)
Sangay said:
4 years ago
A + B + C = 45kg = 3 * 45 = 135,
A+B=40kg=2*40 = 80.
B+C=43kg=2*43 = 86.
Therefore,
80 + 86 = 166.
166-135 = 31.
A+B=40kg=2*40 = 80.
B+C=43kg=2*43 = 86.
Therefore,
80 + 86 = 166.
166-135 = 31.
(26)
Sandeep said:
5 years ago
Thanks @Shree Hema.
Arpit said:
5 years ago
Nice solution. Thanks all.
(1)
SIDHU said:
6 years ago
A+B+C=45*3 PERSONS.
A+B=40.
B+C=43.
SO;
(A+B)+(C+B) = 40+43 = 83,
A+2B+C = 83 * 2 = 166,
B = 166 - 135 = 31.
A+B=40.
B+C=43.
SO;
(A+B)+(C+B) = 40+43 = 83,
A+2B+C = 83 * 2 = 166,
B = 166 - 135 = 31.
(3)
BHUWAN JOSHI said:
7 years ago
@Shree Hema.
135-86 = 49 not 41,
than 49+ B=80,
So, B=31 Years.
135-86 = 49 not 41,
than 49+ B=80,
So, B=31 Years.
Dora said:
7 years ago
ABC is (45*3)=135,
AB is (40*2)=80,
BC is (43*2)=86.
Now;
A+B+C=135,
'-----' +C=135,
80+C=135,
C=135-80,
C=55.
So,B+C=86.
B+55=86.
B=31.
AB is (40*2)=80,
BC is (43*2)=86.
Now;
A+B+C=135,
'-----' +C=135,
80+C=135,
C=135-80,
C=55.
So,B+C=86.
B+55=86.
B=31.
(8)
Raja sadhukhan said:
7 years ago
The average weight of A B and C is 45*3=135,
A,B is 2 person so 40*2=80,
B and C-43*2=86,
(80+86)-135,
= 31.
A,B is 2 person so 40*2=80,
B and C-43*2=86,
(80+86)-135,
= 31.
(2)
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