Effective rate of interest

Find the interest rates earned on each of the following. Round each answer to two decimal places.

You borrow $750 and promise to pay back $780 at the end of 1 year.

%

You lend $750 and the borrower promises to pay you $780 at the end of 1 year.

%

You borrow $70,000 and promise to pay back $88,674 at the end of 8 years.

%

You borrow $8,000 and promise to make payments of $2,219.30 at the end of each year for 5 years.

%