Does anyone know how to solve this Expand (c+d)^9??

Which equation expression the relationship between the number of boxes b and the number of cans c and the proportion is 48

Answer pls man im trying to get out of summer school

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?