The following are exercises on internal rates of return:

a. An investment of $1,000 today will return $2,000 at the end of 10 years. What is its internal rate of return?

b. An investment of $1,000 will return $500 at the end of each of the next 3 years. What is its internal rate of return?

c. An investment of $1,000 today will return $900 at the end of 1 year, $500 at the end of 2 years, and $100 at the end of 3 years. What is its internal rate of return?

d. An investment of $1,000 will return $130 per year forever. What is its internal rate of return?