What are 3 websites that talk about density of different gases, density in air, behavior of different gases of earth, convection? plz i need

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?

Ais a built in formula in spread spread a is any math process such as addition or subtraction. options are function and operation

In simple terms, how would you define a protocol?