Question

The average weight of a b c is 45kg. If the average weiggt of a and b be 40 kg and that of b and c be 43kg then the weight of b is ?

Answer 1

Answer:

Step-by-step explanation:

(a+b+c)/3=45

a+b+c=135-----(1)

(a+b)/2=40

a+b=80-------(2)

(b+c)/2=43

b+c=86------(3)

add(2) and (3)

a+b+c+b=80+86=166

135+b=166

b=166-135=31 Kg

Answer 2

The weight of b is 31 kg

Solution:

The mean is given as:

$Mean = \frac{ \text { sum of all observations }}{ \text{ number of observations }}$

Given that,

The average weight of a b c is 45 kg

Therefore,

$45 = \frac{a + b + c }{3}\\\\a + b + c = 45 \times 3\\\\a + b + c = 135 ------ eqn\ 1$

The average weight of a and b be 40 kg

Therefore,

$40 = \frac{a + b}{2}\\\\a + b = 80 ------- eqn\ 2$

The average weight of b and c be 43 kg

Therefore,

$43 = \frac{b + c}{2}\\\\b + c = 86 ------ eqn\ 3$

Solve eqn 1 and eqn 2 and eqn 3

Add eqn 2 and eqn 1

a + b + b + c = 80 + 86

a + b + c + b = 166

Substitute eqn 1 in above

135 + b = 166

b = 166 - 135

b = 31

Thus weight of b is 31 kg

Learn more about this topic

The average weight of a group of 53 girls was calculated as 58 kg. It was later discovered that the weight of one of the girls was read as 65 kg, whereas her actual weight was 45kg. What is the actual average weight of the group of the 53 girls?

https://brainly.in/question/8246597

The average weight of a class of students is 67.5 kg. The weight of the class teacher is 25% more than the average weight of the class. The average weight of the class is less than the class teacher by x%. The value of x is:

https://brainly.in/question/3531763