If 5/8 of the people in the water aerobics class are over age 65 and 1/4 of the people in the class are under age 40. what fraction of the people in the class are either over 65 or under 40?

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?

Mr. t has been dating his girlfriend for one year nine months and six days how many hours has mr. t been in a relationship

The ideal weight of a nickel is 0.176 ounce. to check that there are 40 nickels in a roll, a bank weighs the roll and allows for an error of 0.015 ounce in total weight