What is the weight of the teacher? Statement I: In a class of 20 students the average weight of students is 21 kg. and it increases to x if the weight of teacher is included. Statement II: In a class of 10 students the average weight of students and teacher is 22 kg.

Statement I: Average of 20 students is 21 kg, so total student weight = 20×21 = 420 kg. 'Increases to x if teacher is included' doesn't give a numerical value for x - it's a variable, not a specific number. This statement is incomplete. Statement II: Average of 10 students AND teacher is 22 kg. This gives total = 11×22 = 242 kg, but we don't know individual student weights. Combining both doesn't help as they refer to different class sizes (20 vs 10 students) and we still lack complete information. Both statements together are insufficient.