### 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:

**A.** 17 kg

**B.** 20 kg

**C.** 26 kg

**D.** 31 kg

## Show Answer

###
Answer-D

Solution-

__Solution(By Apex Team)__

Let A, B, C represent their respective weights.
Then, we have :
$\begin{array}{l}\text{A + B + C = (45 × 3) = 135…..(i)}\\
\text{A + B = (40 × 2) = 80…..(ii)}\\
\text{B + C = (43 × 2) = 86…..(iii)}\\
\text{Adding (ii) and (iii), we get:}\\
\text{A + 2B + C = 166…..(iv)}\end{array}$
Subtracting (i) from (iv), we get: B = 31
∴ B’s weight = 31 kg