Can a moderator

i can't change my name on here although i have tried countless times it doesnt work can someone me? ?

Our primary purpouse as electricians is to do wich of the following core concepts? a: install electrical components in a way they can be upgraded b: install electrical equiptment in a way that reduces heat c: install electrical systems in a safe manner d: only b and c

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 are the three uses of a screw?