Attached are two images of two problems and my two solutions. I feel fairly comfortable with 7-11 but would like you to double check it. 7-13 does not have a good example in the book. I did a present worth calculation and solved for i - it was a quadratic equation. However, I get 0% and 50% as my answer. This is counter-intuitive. Where did I go wrong?
7.11 is incorrect. the correct answer is 10% and not 11%. The step x=-1331 and
is incorrect. You cannot break the euqtion like this.
7.13 As the sign for cash flows is changing twice, we will have two values of IRR in this ...