What does the sales discount 2/10, n/30 mean?

Multiple choice question.

You can take a 10% discount if you pay within 2 days, or the full amount is due within 30 days.

For every day the bill is overdue past 10 days, you will be charged 2% interest.

You can take a 10% discount if you pay within 2 days, or a 30% discount if you pay today.

You can take a 2% discount if you pay within 10 days, or the full amount is due within 30 days.