In shop there are 10 bulbs, a total of 4 are defective. If a customer buys 4 bulbs selected at random from the box, what is the probability that neither bulbs will be defective?	Choose the correct choice from the following:
A) 2/19
B) 3/29
C) 4/15
D) 1/15
E) 1/2
First, there are 6C4 ways you can select 6 good bulbs from 4 good ones.   Second, there are 10C4 ways you select 4 bulbs from 10 ones in the box.   Then, the probability that neither bulb will be defective is: 6C4/10C4=15/210 = 1/15   Answer is 1/15
<result>D</result>
In shop there are 10 bulbs, a total of 4 are defective. If a customer buys 4 bulbs selected at random from the box, what is the probability that neither bulbs will be defective?