Change 47/53 to a percentage

Iam at home. /: i am playing video games. translate the following statement into symbolic form.

Need this at the city museum, child admission is 6 and adult admission is 9.20. on tuesday, 132 tickets were sold for a total sales of 961.60. how many adult tickets were sold that day?

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?