Question

Suppose the bulb drawn in (i) is not defective and not replaced. Now, bulb is drawn at random from the rest. What is the probability that this bulb is not defective?

Answer 1

After removing 1 non-defective bulb, we have number of remaining bulbs = 19.
Out of these, number of non-defective bulbs = 16 − 1 = 15.

Let E₂ be the event of getting a non-defective bulb.

∴ P(getting a non-defective bulb) = P(E₂) = `("Number of favourable to"  E_2)/"Number of all possible outcomes"`

`= 15/19` 

Thus, the probability that the bulb is non-defective is `15/19`