Benefits of using a layered network model?​

I'm taking a class on how to make a movie, and it offers some apps that would be in the process. the thing is, i don't have any of those ha. if you have any tips on some apps i could use, that would be awesome. i don't have an iphone, so don't suggest any apps like imovie. i know that this is a weird question, but it would be super for me. : )

Assume that there is a 4% rate of disk drive failure in a year. a. if all your computer data is stored on a hard disk drive with a copy stored on a second hard disk drive, what is the probability that during a year, you can avoid catastrophe with at least one working drive? b. if copies of all your computer data are stored on three independent hard disk drives, what is the probability that during a year, you can avoid catastrophe with at least one working drive?

What is estimated time of arrival (eta)? a device that measures the acceleration (the rate of change of velocity) of an item and is used to track truck speeds or taxi cab speeds a gps technology adventure game that posts the longitude and latitude location for an item on the internet for users to find a north/south measurement of position the time of day of an expected arrival at a certain destination and is typically used for navigation applications