A facility makes a 350 purchase with a 210 net 30 provision

A facility makes a $350 purchase with a 2-10 net 30 provision. What is the effective annual interest rate if the facility pays on day 11? On day 30?

2-10 net 30 means facility can enjoy 2% discount if they pay in 10 days, otherwise has to pay whole amount in 30 days.

here in above problem, facility pays after discount offer period, so they avail 0% discount, hence in both the days, effective rate of interest would be 0%.