Base and exponent of 3125​

(98 points) i need with 5 questions. answer definitions are welcomed, but not necessary.

Tracy solved the following problem. which of the statements is true? 9 ÷ 3 + 6 × 2 3 + 6 × 2 9 × 2 18 her answer is correct. her answer is incorrect. she should have multiplied before dividing. her answer is incorrect. she should have multiplied before adding. her answer is incorrect. she should have added before dividing.

School has 204 sixth grade students. if the sixth grade is 30% of the total school, how many students are in the middle school?