Classify each sampling method as simple random, random but not simple random, or neither

Random and simple random samples

1. In a class with 200 males and 300 females, I want to select 50 students for a survey.

• I randomly select 20 males and 30 females for the survey.
• I put all 500 students in a list and randomly select 50 students.
• I randomly select 25 males and 25 females.

2. In my class I have 30 students, there are 5 rows of 6 students each. I want to select
12 students for a survey. Classify each sampling method as simple random, random but not simple
random, or neither.

•   I put all 30 students names in a basket and randomly select 12 students.
• I randomly select two of the five rows and choose all students in each of these rows.
• I randomly select one odd row and one even row and take all students in the chosen rows.