The average weight of A, B and C is 45 kg.

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 47 kg, then the weight of B is:

Quiz

Answer/Solution

39 kg

Steps/Work

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 = (47 x 2) = 94 ….(iii)
Adding (ii) and (iii), we get: A + 2B + C = 174 …. (iv)
Subtracting (i) from (iv), we get : B = 39.
B’s weight = 39 kg.
Answer: A