When planning her crops, Farmer Sue knows that her 15 acres can support apples and pecans. She wants to make $8,500 from her crops. She can make $1,050 per acre of apples (the variable a) and $2,500 per acre of pecans (the variable p). Which equation below would be a constraint in her system of equations?

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?