Find the total number of students in class II? Statement I: The number of students in class I is 66.67% of the total number of students in both classes I and
II. Statement II: The average number of students across classes I, II, and III is 216, and the difference between the total students in classes I and III is 88. Statement III: 37.5% of the students in class I and 25% of the students in class II are girls, and the average of the number of girls in class I and boys in class II is 84.

From statement I, Let the total number of students in class I=2x And the total number of students in class II=1x So, Statement I alone is not sufficient to answer the question. From statement II, The total number of students in classes I, II and III=648 So, Statement II alone is not sufficient to answer the question. From statement III, The number of boys in class I=62.5% The number of boys in class II=75% So, Statement III alone is not sufficient to answer the question. From statements I and III, Let the total number of students in class I=2x And the total number of students in class II=1x 2x*3/8+1x*75/100=84*2 3x/4+3x/4=168 x=112 The total number of students in class II=1*112=112 Both statements I and III together is necessary to answer the question