The average weight of 29 students is 28 kg. By the admission of a new student, the average weight is reduced to 27.5 kg. The weight of the new student is	Choose the most appropriate option:
A) 22 kg
B) 21.6 kg
C) 22.4 kg
D) 13 kg
E) none of these

Rationale: "exp . the total weight of 29 students = 29 * 28 the total weight of 30 students = 30 * 27.5 weight of the new student = ( 30 * 27.5 – 29 * 28 ) = 825 - 812 = 13 answer : d"
Answer: D