Find the interest rate (or rates of return) in each of the following situations.
a. You borrow $700 and promise to pay back $749 at the end of 1 year.
b. You lend $700 and receive a promise to be paid $749 at the end of 1 year.
c. You borrow $85,000 and promise to pay back $201,229 at the end of 10 years.
d. You borrow $9,000 and promise to make payments of $2,684.80 at the end of each of the next 5 years.