Suppose time to event has a distribution with survival function:

1. Explain, why it is a valid survival function (if you think it is not valid, provide also an explanation).
2. Find median survival. 
3. Derive a hazard function for that random variable. 
4. Is hazard increasing, decreasing or does it have a finite nonzero minimum or maximum?

You may provide the answers in the text box, but you may also provide a handwritten solution and take a photo of it, and upload.