Engineering Homework Help

1. Why does it take so much time to complete the software?
2. Why is the cost to develop a software so high?
3. Why is it not possible to discover and fix all the bugs before the software is handed over to the client?
4. Why to spend so much of time and effort in maintaining the existing software?
5. Why do we continue to have difficulty in measuring progress as software is being developed and maintained?

Post the answers to any three questions as per your understanding.