The average weight of 29 students is 28 kg. By the admission of a new student, the average weight is reduced to 27.8 kg. The weight of the new student is  Choose the correct choice from the following choices.
A) 22 kg	B) 21.6 kg	C) 22.4 kg	D) 21 kg	E) 23 kg

Rationale: "the total weight of 29 students = 29 * 28 the total weight of 30 students = 30 * 27.8 weight of the new student = ( 30 * 27.8 – 29 * 28 ) = 834 - 812 = 22 answer : a"
Answer: A