three boxes contains 12 electric bulbs in each one box(1) contains 4 defective bulbs box (2) contains 3 defectives bulbs Box (3) contains 5 defectives bulbs a box is selected randomly and one bulb is drawn 10 what is the probability that the selected bulb is defective

To find the probability that the selected bulb is defective, we need to determine the total number of bulbs and the number of defective bulbs in all three boxes.

In box (1), there are 12 bulbs and 4 of them are defective.
In box (2), there are 12 bulbs and 3 of them are defective.
In box (3), there are 12 bulbs and 5 of them are defective.

First, let's calculate the total number of bulbs:

Total number of bulbs = (Number of bulbs in box 1) + (Number of bulbs in box 2) + (Number of bulbs in box 3)
= (12) + (12) + (12)
= 36

Next, let's calculate the total number of defective bulbs:

Total number of defective bulbs = (Number of defective bulbs in box 1) + (Number of defective bulbs in box 2) + (Number of defective bulbs in box 3)
= (4) + (3) + (5)
= 12

Now, we can find the probability that the selected bulb is defective by dividing the total number of defective bulbs by the total number of bulbs:

Probability = (Total number of defective bulbs) / (Total number of bulbs)
= 12 / 36
= 1 / 3
≈ 0.33

Therefore, the probability that the selected bulb is defective is approximately 0.33 or 33%.