Finance Questions:

1)It appears to be the case--and the mathematics will confirm this--that any project that is acceptable based on IRR will also be acceptable based on MIRR. So why go to all the trouble of calculating MIRR? Isn't that a waste of time, or are there circumstances in which it would seem not just appropriate but necessary?

2)IRR and NPV always agree on the yes/no decision, but they don't always agree on rankings. A and B are both good projects, but IRR says you should pick A and NPV says pick B. What might cause this disagreement, and what should you do about it?