Giving a test to a group of students, the grades and gender are summarized below A B C Total
Male 13 17 20 50
Female 12 9 16 37
Total 25 26 36 87
If one student was chosen at random, find the probability that the student got an A.
Give your answer as a fraction or decimal.

God's gym charges a sign-up fee of $100 plus $30 per month. write an expression to represent how much someone would pay for a membership.

What is the product? a-3/15a × 5/a-3

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?