Answer:
189
Step-by-step explanation:
2/9 of the school = 42 sixth graders
2/9 / 2 = 1/9
42 / 2 = 21
1/9 = 21
21 x 9
20 x 9 = 180
1 x 9 = 9
180 + 9 = 189
9/9 of the school = 189 students