Average Practice Test 4

Mean weight of 34 students = 42 kg.
Total weight of students = 34 × 42 = 1,428 kg.
Mean weight increased = 42 kg + 400 g = 42.4 g
Total weight of 35 persons including the teacher = 42.5 × 35 = 1,484 kg
Weight of the teacher = Total weight including the teacher -Total weight of the students
Weight of the teacher = 1,484 - 1,428 = 56 kg.