The average weight of 5 students decreases by 12 kg when one of them weighing 72 kg is replaced by a new student. The weight of the student is	Options.
A) 12 kg	B) 10 kg	C) 20 kg	D) 72 kg	E) none of these

Rationale: "explanation : let the weight of student be x kg . given , difference in average weight = 12 kg = > ( 72 - x ) / 5 = 12 = > x = 12 answer : a"
Answer: A