### Home > CCA2 > Chapter 12 > Lesson 12.1.2 > Problem12-37

12-37.

Three light bulbs are chosen at random from $15$ bulbs, of which five are defective. What is the probability that:

1. None of the three are defective.

Use combinations to solve this problem. For a review of combinations, see the Math Notes in Lesson 10.1.1.

$\text{Remember that probability =} \frac{\text{# of desirable outcomes}}{\text{# of possible outcomes}}$.

2. Exactly two are defective.

Use the same method as part (a).