What number must be added to 36 to obtain −12

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?

Situation: find the age of the skull to the nearest year, enter the correct answer. a hiker in africa discovers a skull that contains 32% of its original amount of c- 14. done n = noekt 00000 no = inital amount of c-14 (at time t = 0) n = amount of c-14 at time t k = 0.0001 t = time, in years

Charles smith makes $9.75 an hour. he works 4 hours on monday, 6 hours on tuesday, 5 hours on wednesday, 5 hours on thursday, and 7 hours on friday. what is his gross pay?