100 students were asked if they study German, French or Spanish. 40 students study German.
13 students study German, French and Spanish.
19 students study German and Spanish but not French.
18 students study French and Spanish.
41 students do not study any of the languages.
All 25 students who study French also study at
least one other language.
a) Complete the Venn diagram

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?