In a box of 12 pens, a total of 4 are defective. If a customer buys 3 pens selected at random from the box, what is the probability that neither pen will be defective?
Choices.
A) 1/6
B) 2/55
C) 14/55
D) 12/55
E) 3/4
Method- 1   There are 9 fine pieces of pen and 4 defective in a lot of 12 pens   i.e. Probability of first pen NOT being defective = (8/12)   i.e. Probability of Second pen NOT being defective = (7/11)   i.e. Probability of third pen NOT being defective = (6/10)   Probability of Both pen being NON-defective = (8/12)*(7/11)*(6/10) = 14/55   Answer: option 14/55
<result>C</result>
In a box of 12 pens, a total of 4 are defective. If a customer buys 3 pens selected at random from the box, what is the probability that neither pen will be defective?