Can someone please help me with this​

When is an original work considered public domain? a. when posted via social media b. when it is posted on the internet c. when a copyright symbol is not included with the piece of work d. when explicit permission is given by the author / owner

The “rule of 72” is used to approximate the time required for prices to double due to inflation. if the inflation rate is r%, then the rule of 72 estimates that prices will double in 72/r years. for instance, at an inflation rate of 6%, prices double in about 72/6 or 12 years. write a program to test the accuracy of this rule. for each interest rate from 1% to 20%, the program should display the rounded value of 72/r and the actual number of years required for prices to double at an r% inflation rate. (assume prices increase at the end of each year.)

Need asap write a short paper describing the history and differences between six sigma, waterfall, agile, and scrum models. understanding these models can give you a good idea of how diverse and interesting it development projects can be. describe what the rationale for them is and describe their key features. describe the history behind their development. at least 400 words