The average weight of A, B and C is 65 kg. The average weight of A and B is 62 kg and that of B and C is 57 kg. The weight of B is:

Correct option is B

Given:

Average weight of A, B, C is 65 kg

Average weight of A and B is 62 kg

Average weight of B and C is 57 kg

Formula Used:

​$$Average = \frac{Sum\ of\ observations}{Number\ of\ observations}$$​​

Solution:

Total weight of A,B and C is $$65\times 3$$ = 195 kg

Total weight of A and B is  $$62\times 2$$ = 124 kg

Total weight of B and C is $$57\times 2$$ = 114 kg

Weight of C = (Total weight of A, B, C) - (Total weight of A and B)

= 195 - 124 = 71kgs

Weight of B = (Total weight of B and C) - Weight of C

= 114 -71 = 43kgs

Thus, Weight of B is 43 kgs