If sarah reads at an average rate of 21 pages in four nights, how long will it take her to read 140 pages?

The distance around the lake is 2 kilometers. ifelena wants to run 14 kilometers this week, howmany laps must she run around the lake

I’m stuck on this equation, anyone got the answer?

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?