Hi, someone can give me the answers to this exercise please?

3. For each situation below, state the type of sampling technique used.

a) A teacher selects every 5th student on her attendance list in her grade 9 physical education class and asks them to record how many sit-ups they can do in 60 seconds.

b) Tony is working for a political party. He stands at a busy street corner asking people who they plan to vote for in the upcoming election.