Please help me for the first one i need to find the exact and the second one i need to find the approximate volume

Complete each sentence with the correct form of the verb ser or estar to say where the following people are from or where they are right now claudia y maria en méxico

Assume that there is a 11% 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 four independent hard disk drives, what is the probability that during a year, you can avoid catastrophe with at least one working drive?

G. how many different 6-letter arrangements can be formed using the letters in the word absent, if each letter is used only once? a. 6 b. 36 c. 720 d. 46,656