In a box of 11 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?	Options: A) 1/25 B) 28/55 C) 2/35 D) 2/55 E) 1/75
First, there are 9C3 ways you can select 3 good pencils from 4 good ones.   Second, there are 11C3 ways you select 3 pencils from 6 ones in the box.   Then, the probability that neither pen will be defective is: 9C3/11C3=84/165 = 28/55   Answer is 28/55
<result>B</result>
In a box of 11 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?