Assume a class has 17 members. a.  in how many ways can a president, a vice president, and a secretary be selected? b.  how many committees of 5 people can be chosen?

If the ratio of sum of the first m and n terms of an ap is m2 : n2 , show that the ratio of its mth and nth terms is (2m − 1) : (2n − 1).

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?

Cody ran nine miles on his first day of training. the next day he ran 1/8 that distance. how far did he run the second day?