Question

It is known that a box of $600$ electric bulbs contains $12$ defective bulbs. One bulb is taken out at random from this box. What is the probability that it is a non-defective bulb?

Answer 1

Step 1: Find the number of non-defective bulbs:

The total number of electric bulbs are $600$

The number of defective bulbs are $12$

Thus, the number of non-defective bulbs are $600-12=588$

Step 2: Use the formula for probability:

$\text{Probability =}\frac{\text{Number of non-defective bulbs}}{\text{Total number of bulbs}}$

Thus, the probability will be,

$$\begin{gathered} \text{Probability=}\frac{588}{600} \\ \mathrm{Probability}\text{=}\frac{49}{50} \end{gathered}$$

Hence, the probability of getting a non-defective bulb is $\frac{49}{50}$.