Question

At a convention there are 7 mathematics instructors, 5 computer science instructors, 3 history instructors, and 4 english instructors. If an instructor is selected, find the probability of getting a computer science instructor or a mathematics instructor

Answer 1

12/19.

Explanation:

There are 19 instructors altogether.

Probability (getting a computer science instructor) = 5/19.

Probability (getting a mathematics instructor) = 7/19.

As this a 'compounded or' probability these values are added so the answer is 5/19 + 7/19

= 12/19.