SOLUTION: A sample of 100 wood and 100 graphite tennis rackets are taken from the warehouse. If 9 wood and 19 graphite are defective and one racket is randomly selected from the sample, fin

Algebra ->  Probability-and-statistics -> SOLUTION: A sample of 100 wood and 100 graphite tennis rackets are taken from the warehouse. If 9 wood and 19 graphite are defective and one racket is randomly selected from the sample, fin      Log On


   

Question 994434: A sample of 100 wood and 100 graphite tennis rackets are taken from the warehouse. If 9 wood
and 19 graphite are defective and one racket is randomly selected from the sample, find the probability that the racket is wood or defective.
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
Or means either one.
Table
Wood ;;;;;;;;;;; Graphite ;;; Total
Defective;;;;;; 9 ;;;;;;;;;;; 19;;; ;;28
non-D;;;;;; 91 ;;;;;;;;;;;;;;; 81;;;;;;;172
Total---------100--------------100-------200
Probability Wood is (100/200)
Probability defective is (28/200)
Probability BOTH is (9/200)
The answer is the sum of the first two minus the third, since we have double counted.
It is (100+28-9)/200=(119/200). It is the everything but graphite and non-defective.