The average weight of 6 person's increases by 1.8 kg when a new person comes in place of one of them weighing 69 kg. What might be the weight of the new person?  Answers:
A) 73 kg B) 79.8 kg C) 86 kg D) data inadequate E) none of these

Rationale: "total weight increased = ( 6 x 1.8 ) kg = 10.8 kg . weight of new person = ( 69 + 10.8 ) kg = 79.8 kg . answer : option b"
Answer: B