Sorry but can you please help

Mr.zimmerman invested $25,000 in an account that draws 1.4 interest, compouneded annually. what is the total value of the account after 15 years

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?

The actual length of side t is 0.045cm. use the scale drawing to find the actual side length of w