The average weight of D, E and F is 42 kg. If the average weight of D and E be 35 kg and that of E and F be 41 kg, what is the weight of E? Choose the correct choice from the following answers:
A) 23 kg B) 24 kg C) 25 kg D) 26 kg E) 27 kg

Rationale: let the weight of d , e and f are a , b and c respectively . average weight of d , e and f = 42 a + b + c = 42 × 3 = 126 - - - equation ( 1 ) average weight of d and e = 35 a + b = 35 × 2 = 70 - - - equation ( 2 ) average weight of e and f = 41 b + c = 41 × 2 = 82 - - - equation ( 3 ) equation ( 2 ) + equation ( 3 ) - equation ( 1 ) = > a + b + b + c - ( a + b + c ) = 70 + 82 - 126 = > b = 152 - 126 = 26 weight of b = 26 kg answer : d
Answer: D