David and amrita had an equal number of marbles. after armita gave 50 marbles to david he had 5 times as many marbles as her. find the total number of marbles they had.

Which data set has a greater spread? why? set a: {38, 12, 23, 48, 55, 16, 18} set b: {44, 13, 24, 12, 56} has a greater spread because .

If my mom gets $13.05 an hour, and she works from 3: 30 to 10: 45 in the morning, how much money does my mom make?

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?