In a box of 9 pencils, a total of 2 are defective. If a customer buys 3 pencils selected at random from the box, what is the probability that neither pencils will be defective?  Select the correct option: A) 5/12 B) 1/15 C) 2/13 D) 2/15 E) 1/17
First, there are 7C3 ways you can select 3 good pencils from 4 good ones.   Second, there are 9C3 ways you select 3 pencils from 6 ones in the box.   Then, the probability that neither pen will be defective is: 7C3/9C3=35/84 = 5/12   5/12nswer is 5/12
<result>A</result>
In a box of 9 pencils, a total of 2 are defective. If a customer buys 3 pencils selected at random from the box, what is the probability that neither pencils will be defective?